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 A373621 #23 Jun 11 2024 15:49:38
%S A373621 1,1,1,1,1,26,31,36,41,46,676,881,1111,1366,1646,17576,24281,32386,
%T A373621 42016,53296,456976,658806,916411,1238666,1635071,11881376,17706456,
%U A373621 25462936,35569066,48496846,308915776,472880356,698851961,1003283216,1405555496,8031810176
%N A373621 Expansion of 1 / ( (1 - 25*x^5) * (1 - x/(1 - 25*x^5)^(1/5)) ).
%F A373621 a(5*n) = 26^n for n >= 0.
%F A373621 a(n) = Sum_{k=0..floor(n/5)} 25^k * binomial(n/5,k).
%F A373621 a(n) == 1 (mod 5).
%o A373621 (PARI) a(n) = sum(k=0, n\5, 25^k*binomial(n/5, k));
%Y A373621 Cf. A000079, A100095, A373278, A373583.
%Y A373621 Cf. A373510.
%K A373621 nonn
%O A373621 0,6
%A A373621 _Seiichi Manyama_, Jun 11 2024