400 (liczba) (Polish Wikipedia)

Analysis of information sources in references of the Wikipedia article "400 (liczba)" in Polish language version.

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Global rank Polish rank

742^nd place

1,271^st place

oeis.org

Niven (or Harshad) numbers: numbers that are divisible by the sum of their digits.. The On-Line Encyclopedia of Integer Sequences. [dostęp 2017-03-14]. (ang.).
Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = least number > a(n-1) which is a unique sum of two distinct earlier terms.. The On-Line Encyclopedia of Integer Sequences. [dostęp 2017-03-16]. (ang.).
Practical numbers: positive integers n such that every k ⇐ sigma(n) is a sum of distinct divisors of n. Also called panarithmic numbers.. The On-Line Encyclopedia of Integer Sequences. [dostęp 2017-03-16]. (ang.).
The squares: a(n) = n^2.. The On-Line Encyclopedia of Integer Sequences. [dostęp 2017-03-16]. (ang.).