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 A373278 #25 Jun 21 2024 08:44:53
%S A373278 1,1,1,10,13,16,100,148,205,1000,1606,2410,10000,17005,27070,100000,
%T A373278 177421,295648,1000000,1833178,3168538,10000000,18811948,33503020,
%U A373278 100000000,192080866,350707345,1000000000,1953820210,3642942040,10000000000,19815499120,37611477133
%N A373278 Expansion of 1 / ( (1 - 9*x^3) * (1 - x/(1 - 9*x^3)^(1/3)) ).
%F A373278 a(3*n) = 10^n for n >= 0.
%F A373278 a(n) = Sum_{k=0..floor(n/3)} 9^k * binomial(n/3,k).
%F A373278 a(n) == 1 (mod 3).
%F A373278 D-finite with recurrence (n-1)*(n-2)*a(n) +2*(-14*n^2+69*n-91)*a(n-3) +9*(n-3)*(29*n-114)*a(n-6) -810*(n-3)*(n-6)*a(n-9)=0. - _R. J. Mathar_, Jun 21 2024
%o A373278 (PARI) a(n) = sum(k=0, n\3, 9^k*binomial(n/3, k));
%Y A373278 Cf. A000079, A100095, A373583, A373621.
%Y A373278 Cf. A011557, A371458.
%K A373278 nonn
%O A373278 0,4
%A A373278 _Seiichi Manyama_, Jun 11 2024