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 A293464 #8 Oct 09 2017 19:18:03
%S A293464 1,-1,7,-17,63,-161,543,-1377,4255,-11105,31903,-82785,232607,-594785,
%T A293464 1617055,-4150113,10988703,-27939681,72985759,-183915361,473541791,
%U A293464 -1187402593,3015290015,-7512413025,18911702175,-46787875681,116689317023,-287306044257
%N A293464 a(n) = Sum_{k=0..n} (-1)^k * 2^k * p(k), where p(k) is the partition function A000041.
%H A293464 Vaclav Kotesovec, <a href="/A293464/b293464.txt">Table of n, a(n) for n = 0..1000</a>
%F A293464 a(n) ~ (-1)^n * 2^(n-1) * exp(Pi*sqrt(2*n/3)) / (3^(3/2)*n).
%F A293464 a(n) ~ (-1)^n * 2/3 * 2^n * A000041(n).
%t A293464 Table[Sum[(-1)^k * 2^k * PartitionsP[k], {k, 0, n}], {n, 0, 30}]
%Y A293464 Cf. A087787, A259400.
%K A293464 sign
%O A293464 0,3
%A A293464 _Vaclav Kotesovec_, Oct 09 2017