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 A321345 #11 Nov 07 2018 03:11:48
%S A321345 1,5,15,35,86,206,450,890,1751,3411,6401,11405,20076,35036,59876,
%T A321345 99156,162345,263821,422871,663691,1031914,1594610,2440286,3678886,
%U A321345 5504759,8196659,12117745,17715581,25744904,37267624,53652824,76576760,108763319,153984019,217058009
%N A321345 Expansion of 1/(1 - x) * Product_{k>=0} 1/(1 - x^(4^k))^(4^(k+1)).
%C A321345 Also the coefficient of x^(4*n) in the expansion of Product_{k>=0} 1/(1 - x^(4^k))^(4^k).
%e A321345 Product_{k>=0} 1/(1 - x^(4^k))^(4^k) = 1 + x + x^2 + x^3 + 5*x^4 + 5*x^5 + 5*x^6 + 5*x^7 + 15*x^8 + 15*x^9 + 15*x^10 + 15*x^11 + 35*x^12 + 35*x^13 + 35*x^14 + 35*x^15 + ... .
%o A321345 (PARI) seq(n)={Vec(1/((1 - x)*prod(k=0, logint(n,4), (1 - x^(4^k) + O(x*x^n))^(4^(k+1)))))} \\ _Andrew Howroyd_, Nov 06 2018
%Y A321345 Cf. A321335, A321344.
%K A321345 nonn
%O A321345 0,2
%A A321345 _Seiichi Manyama_, Nov 06 2018