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 A341557 #12 Mar 31 2023 03:00:39
%S A341557 0,1,30,333,1444,-570,-21114,-22576,121848,64233,-276300,589260,
%T A341557 -1198764,133766,-957216,2920590,2491792,-1616958,1647054,-5312428,
%U A341557 -14819880,-4158576,20300904,16879848,19051416,-22583225,38165172,-81066987,-47716288,66118494,370980,-51834232
%N A341557 Fourier coefficients of the modular form (1/t_{3A}) * F_{3A}^12.
%H A341557 Masao Koike, <a href="/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, Unpublished manuscript [Extensively annotated with OEIS A-numbers by N. J. A. Sloane, Feb 14 2021. Sloane wrote 2005 on the first page but the internal evidence suggests 1997.] See page 30.
%F A341557 Convolution product of 1/A030197 and A008655^3. - _Georg Fischer_, Mar 31 2023
%Y A341557 Cf. A008655, A030197, A341556, A341558, A341561.
%K A341557 sign
%O A341557 0,3
%A A341557 _Robert C. Lyons_, Feb 14 2021
%E A341557 More terms from _Georg Fischer_, Mar 31 2023