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 A373627 #10 Jun 11 2024 15:49:34
%S A373627 1,1,1,1,9,11,13,15,81,109,141,177,729,1041,1429,1901,6561,9759,13981,
%T A373627 19419,59049,90483,133893,192327,531441,832911,1264173,1865539,
%U A373627 4782969,7628799,11816853,17828163,43046721,69620541,109646397,168500385,387420489,633634769
%N A373627 Expansion of 1 / ( (1 - 8*x^4) * (1 - x/(1 - 8*x^4)^(1/4)) ).
%F A373627 a(4*n) = 9^n for n >= 0.
%F A373627 a(n) = Sum_{k=0..floor(n/4)} 8^k * binomial(n/4,k).
%F A373627 a(n) == 1 (mod 2).
%o A373627 (PARI) a(n) = sum(k=0, n\4, 8^k*binomial(n/4, k));
%Y A373627 Cf. A373509, A373583.
%K A373627 nonn
%O A373627 0,5
%A A373627 _Seiichi Manyama_, Jun 11 2024