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 A336978 #18 May 01 2021 17:43:25
%S A336978 1,-1,-2,-2,0,3,8,11,9,8,-10,-31,-57,-58,-107,-85,-4,120,167,383,616,
%T A336978 905,948,479,-82,-125,-905,-3661,-5937,-8247,-8807,-7756,-6249,-8147,
%U A336978 -3525,8330,30748,54740,82660,85406,86083,109681,148897,148077,81288,-57885,-257092,-490304
%N A336978 Expansion of Product_{k>=1} (1 - x^k * (1 + k*x)).
%H A336978 Seiichi Manyama, <a href="/A336978/b336978.txt">Table of n, a(n) for n = 0..1000</a>
%F A336978 G.f.: exp( - Sum_{k>=1} x^k * Sum_{d|k} (1 + k/d * x)^d / d).
%t A336978 m = 47; CoefficientList[Series[Product[1 - x^k*(1 + k*x), {k, 1, m}], {x, 0, m}], x] (* _Amiram Eldar_, May 01 2021 *)
%o A336978 (PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, 1-x^k*(1+k*x)))
%o A336978 (PARI) N=66; x='x+O('x^N); Vec(exp(-sum(k=1, N, x^k*sumdiv(k, d, (1+k/d*x)^d/d))))
%Y A336978 Convolution inverse of A336976.
%Y A336978 Cf. A306565, A336975, A336978, A336979, A336980.
%K A336978 sign
%O A336978 0,3
%A A336978 _Seiichi Manyama_, Aug 09 2020