This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A374499 #10 Jul 11 2024 13:16:22 %S A374499 36,560,4900,56448,4750,58372180608,1130220,6252757280000 %N A374499 Least n-gonal pyramidal number that can be written as a product of two or more smaller n-gonal pyramidal numbers, or 0 if no such number exists. %C A374499 a(11) = 4200, a(13) = 5521090680, a(14) = 748980. %e A374499 For 2 <= n <= 9, the n-gonal pyramidal number a(n) can be written as a product of smaller n-gonal pyramidal numbers in the following ways: %e A374499 n | a(n) %e A374499 --+------------------------------------- %e A374499 2 | 36 = 6*6 %e A374499 3 | 560 = 4*4*35 = 10*56 %e A374499 4 | 4900 = 5*5*14*14 %e A374499 5 | 56448 = 196*288 %e A374499 6 | 4750 = 50*95 %e A374499 7 | 58372180608 = 196*456*653108 %e A374499 8 | 1130220 = 9*70*1794 %e A374499 9 | 6252757280000 = 10*10*10*80*78159466 %Y A374499 Second column of A374498. %Y A374499 Cf. A080851, A374371. %K A374499 nonn,more %O A374499 2,1 %A A374499 _Pontus von Brömssen_, Jul 09 2024