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 A341304 #16 Jul 23 2023 17:07:20
%S A341304 1,-84,-82,-456,4869,-2524,-10778,6888,-11150,4124,38304,81704,-71401,
%T A341304 -225288,99798,-40480,212016,37392,-419442,905352,141402,-690428,
%U A341304 -399258,-682032,-615607,936600,1813118,206968,-346416,-966028,1887670,-2220264,883796,2965868
%N A341304 Fourier coefficients of a modular form studied by Koike.
%C A341304 This is the form (1/t_{4a}) * ( 1-16*i/t_{4a} )*F_{4a}^8. Here, F_{4a} is the hypergeometric function F(1/4, 1/2; 1; 32*i/t_{4a}).
%H A341304 Masao Koike, <a href="https://oeis.org/A004016/a004016.pdf">Modular forms on non-compact arithmetic triangle groups</a>, Unpublished manuscript [Extensively annotated with OEIS A-numbers by N. J. A. Sloane, Feb 14 2021. I wrote 2005 on the first page but the internal evidence suggests 1997.] See page 29.
%o A341304 (Sage)
%o A341304 def a(n):
%o A341304 eta = x^(1/24)*product([(1 - x^k) for k in range(1, 2*n+1)])
%o A341304 t4a = ((eta/eta(x=x^2))^12 - 64*(eta(x=x^2)/eta)^12) + 16*sqrt(-1)
%o A341304 F4a = sum([rising_factorial(1/4,k)*rising_factorial(1/2,k)/
%o A341304 (rising_factorial(1,k)^2)*((32*sqrt(-1))/t4a)^k for k in range(2*n+1)])
%o A341304 f = (1/t4a)*(1 - 16*sqrt(-1)/t4a)*(F4a^8)
%o A341304 return f.taylor(x,0,n+1).coefficients()[n][0] # _Robin Visser_, Jul 23 2023
%Y A341304 Cf. A341305, A341306.
%K A341304 sign
%O A341304 0,2
%A A341304 _N. J. A. Sloane_, Feb 13 2021
%E A341304 More terms from _Robin Visser_, Jul 23 2023