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 A306663 #5 Mar 04 2019 23:15:26
%S A306663 1,0,1,1,1,1,2,2,4,4,8,8,17,17,35,38,74,80,161,173,336,387,713,818,
%T A306663 1555,1765,3248,3923,6905,8282,15012,17814,31419,39321,66679,82923,
%U A306663 144789,177721,302789,390123,642640,821316,1390825,1755400,2910638,3833338,6165743,8060128,13322378
%N A306663 Expansion of Sum_{k>=0} x^(k*(k+1)) / Product_{j=1..k} (1 - j*x^j).
%t A306663 nmax = 48; CoefficientList[Series[Sum[x^(k (k + 1))/Product[(1 - j x^j), {j, 1, k}], {k, 0, nmax}], {x, 0, nmax}], x]
%Y A306663 Cf. A003106, A193196, A204856.
%K A306663 nonn
%O A306663 0,7
%A A306663 _Ilya Gutkovskiy_, Mar 04 2019