For instance, Gardner (1978) shows two orientations, both different from the one here. Gardner, Martin (1978), "The Bells: versatile numbers that can count partitions of a set, primes and even rhymes", Scientific American, 238: 24–30, Bibcode:1978SciAm.238e..24G, doi:10.1038/scientificamerican0578-24. Reprinted with an addendum as "The Tinkly Temple Bells", Chapter 2 of Fractal Music, Hypercards, and more ... Mathematical Recreations from Scientific American, W. H. Freeman, 1992, pp. 24–38.
For instance, Gardner (1978) shows two orientations, both different from the one here. Gardner, Martin (1978), "The Bells: versatile numbers that can count partitions of a set, primes and even rhymes", Scientific American, 238: 24–30, Bibcode:1978SciAm.238e..24G, doi:10.1038/scientificamerican0578-24. Reprinted with an addendum as "The Tinkly Temple Bells", Chapter 2 of Fractal Music, Hypercards, and more ... Mathematical Recreations from Scientific American, W. H. Freeman, 1992, pp. 24–38.