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 A333009 #15 Mar 09 2020 14:49:36 %S A333009 5,3,6,5,10,4,20,17,8,1,7,2,1,1,8,1,3,8,7,2,4,4,3,11,6,4,3,9,5,7,5,3, %T A333009 1,2,2,1,3,2,6,1,24,1,6,1,9,8,14,4,5,4,5,5,9,2,3,2,14,3,6,8,4,2,4,10, %U A333009 1,2,7,1,6,8,6,7,1,8,5,7,12,8,4,4,5,2,11,4 %N A333009 Successive differences of A333008 (square roots of perfect squares that are the sum of two nonzero pentagonal numbers). %C A333009 The behavior of this sequence is unexpectedly quite complex. %H A333009 Peter Kagey, <a href="/A333009/b333009.txt">Table of n, a(n) for n = 1..1000</a> %Y A333009 Cf. A332986 (analog for indices of triangular numbers). %Y A333009 Cf. A000326, A333007, A333008. %K A333009 nonn %O A333009 1,1 %A A333009 _Olivier Gérard_, Mar 05 2020