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 A294402 #14 Aug 17 2021 10:10:49
%S A294402 1,-1,-3,-1,1,279,301,12263,5601,-431281,-2140739,-77720721,
%T A294402 -1755429983,-12569445721,85768062381,-4458503862121,43351731658561,
%U A294402 546719071653663,31735514726673661,291860504886837599,5860390638855992001,208620917963122666679
%N A294402 E.g.f.: exp(-Sum_{n>=1} d(n) * x^n), where d(n) is the number of divisors of n.
%H A294402 Seiichi Manyama, <a href="/A294402/b294402.txt">Table of n, a(n) for n = 0..448</a>
%F A294402 a(0) = 1 and a(n) = (-1) * (n-1)! * Sum_{k=1..n} k*A000005(k)*a(n-k)/(n-k)! for n > 0.
%F A294402 E.g.f.: Product_{k>=1} (1 - x^k)^f(k), where f(k) = (1/k) * Sum_{j=1..k} gcd(k,j). - _Ilya Gutkovskiy_, Aug 17 2021
%o A294402 (PARI) N=66; x='x+O('x^N); Vec(serlaplace(exp(-sum(k=1, N, numdiv(k)*x^k))))
%Y A294402 E.g.f.: exp(-Sum_{n>=1} sigma_k(n) * x^n): this sequence (k=0), A294403 (k=1), A294404 (k=2).
%Y A294402 Cf. A000005, A018804, A028343, A294363.
%K A294402 sign
%O A294402 0,3
%A A294402 _Seiichi Manyama_, Oct 30 2017