Triangular number (English Wikipedia)

Beldon, Tom; Gardiner, Tony (2002). "Triangular Numbers and Perfect Squares". The Mathematical Gazette. 86 (507): 423–431. doi:10.2307/3621134. JSTOR 3621134. Retrieved 25 April 2024.

mathcircles.org (Global: low place; English: low place)

"The Handshake Problem | National Association of Math Circles". MathCircles.org. Archived from the original on 10 March 2016. Retrieved 12 January 2022.

mathsisfun.com (Global: 6,108^th place; English: 4,433^rd place)

"Triangular Number Sequence". Math Is Fun.

semanticscholar.org (Global: 11^th place; English: 8^th place)

api.semanticscholar.org

Baumann, Michael Heinrich (2018-12-12). "Die $k$ -dimensionale Champagnerpyramide" (PDF). Mathematische Semesterberichte (in German). 66: 89–100. doi:10.1007/s00591-018-00236-x. ISSN 1432-1815. S2CID 125426184.
Liu, Zhi-Guo (2003-12-01). "An Identity of Ramanujan and the Representation of Integers as Sums of Triangular Numbers". The Ramanujan Journal. 7 (4): 407–434. doi:10.1023/B:RAMA.0000012425.42327.ae. ISSN 1382-4090. S2CID 122221070.
Engelstein, Geoffrey; Shalev, Isaac (2019-06-25). Building Blocks of Tabletop Game Design. doi:10.1201/9780429430701. ISBN 978-0-429-43070-1. S2CID 198342061.
Stone, John David (2018), Algorithms for Functional Programming, Springer, p. 282, doi:10.1007/978-3-662-57970-1, ISBN 978-3-662-57968-8, S2CID 53079729

stir.ac.uk (Global: low place; English: 9,306^th place)

dspace.stir.ac.uk

Ross, H.E.; Knott, B.I. (2019). "Dicuil (9th century) on triangular and square numbers". British Journal for the History of Mathematics. 34 (2): 79–94. doi:10.1080/26375451.2019.1598687. hdl:1893/29437.

uni-bayreuth.de (Global: low place; English: low place)

epub.uni-bayreuth.de

Baumann, Michael Heinrich (2018-12-12). "Die $k$ -dimensionale Champagnerpyramide" (PDF). Mathematische Semesterberichte (in German). 66: 89–100. doi:10.1007/s00591-018-00236-x. ISSN 1432-1815. S2CID 125426184.

uregina.ca (Global: low place; English: 6,461^st place)

mathcentral.uregina.ca

Eves, Howard. "Webpage cites AN INTRODUCTION TO THE HISTORY OF MATHEMATICS". Mathcentral. Retrieved 28 March 2015.

web.archive.org (Global: 1^st place; English: 1^st place)

Hayes, Brian. "Gauss's Day of Reckoning". American Scientist. Computing Science. Archived from the original on 2015-04-02. Retrieved 2014-04-16.
"The Handshake Problem | National Association of Math Circles". MathCircles.org. Archived from the original on 10 March 2016. Retrieved 12 January 2022.

wolfram.com (Global: 513^th place; English: 537^th place)

mathworld.wolfram.com

Eric W. Weisstein. "Triangular Number". Wolfram MathWorld. Retrieved 2024-04-14. See equations 18 - 20.

demonstrations.wolfram.com

http://demonstrations.wolfram.com/GeometricProofOfTheTetrahedralNumberFormula

worldcat.org (Global: 5^th place; English: 5^th place)

search.worldcat.org

Baumann, Michael Heinrich (2018-12-12). "Die $k$ -dimensionale Champagnerpyramide" (PDF). Mathematische Semesterberichte (in German). 66: 89–100. doi:10.1007/s00591-018-00236-x. ISSN 1432-1815. S2CID 125426184.
Liu, Zhi-Guo (2003-12-01). "An Identity of Ramanujan and the Representation of Integers as Sums of Triangular Numbers". The Ramanujan Journal. 7 (4): 407–434. doi:10.1023/B:RAMA.0000012425.42327.ae. ISSN 1382-4090. S2CID 122221070.

Triangular number (English Wikipedia)

americanscientist.org (Global: 7,231st place; English: 5,635th place)

archive.org (Global: 6th place; English: 6th place)

arxiv.org (Global: 69th place; English: 59th place)

books.google.com (Global: 3rd place; English: 3rd place)

doi.org (Global: 2nd place; English: 2nd place)

doi.org

dx.doi.org

emis.de (Global: low place; English: low place)

handle.net (Global: 102nd place; English: 76th place)

hdl.handle.net

henders.one (Global: low place; English: low place)

jstor.org (Global: 26th place; English: 20th place)

mathcircles.org (Global: low place; English: low place)

mathsisfun.com (Global: 6,108th place; English: 4,433rd place)

semanticscholar.org (Global: 11th place; English: 8th place)

api.semanticscholar.org

stir.ac.uk (Global: low place; English: 9,306th place)

dspace.stir.ac.uk

uni-bayreuth.de (Global: low place; English: low place)

epub.uni-bayreuth.de

uregina.ca (Global: low place; English: 6,461st place)

mathcentral.uregina.ca

web.archive.org (Global: 1st place; English: 1st place)

wolfram.com (Global: 513th place; English: 537th place)

mathworld.wolfram.com

demonstrations.wolfram.com

worldcat.org (Global: 5th place; English: 5th place)

search.worldcat.org

americanscientist.org (Global: 7,231^st place; English: 5,635^th place)

archive.org (Global: 6^th place; English: 6^th place)

arxiv.org (Global: 69^th place; English: 59^th place)

books.google.com (Global: 3^rd place; English: 3^rd place)

doi.org (Global: 2^nd place; English: 2^nd place)

handle.net (Global: 102^nd place; English: 76^th place)

jstor.org (Global: 26^th place; English: 20^th place)

mathsisfun.com (Global: 6,108^th place; English: 4,433^rd place)

semanticscholar.org (Global: 11^th place; English: 8^th place)

stir.ac.uk (Global: low place; English: 9,306^th place)

uregina.ca (Global: low place; English: 6,461^st place)

web.archive.org (Global: 1^st place; English: 1^st place)

wolfram.com (Global: 513^th place; English: 537^th place)

worldcat.org (Global: 5^th place; English: 5^th place)