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 A302546 #12 Jul 15 2018 13:21:48
%S A302546 0,2,6,18,98,2114,1114242,68723671298,1180735735906024030722,
%T A302546 170141183460507917357914971986913657858,
%U A302546 7237005577335553223087828975127304179197147198604070555943173844710572689410
%N A302546 a(n) = Sum_{k = 1...n} 2^binomial(n, k).
%F A302546 a(n) = A001315(n) - 2.
%t A302546 Table[Sum[2^Binomial[n,d],{d,n}],{n,10}]
%o A302546 (PARI) a(n) = sum(k=1, n, 2^binomial(n, k)); \\ _Michel Marcus_, Jun 21 2018
%Y A302546 Cf. A001315, A003465, A034729, A055621, A302545.
%K A302546 nonn
%O A302546 0,2
%A A302546 _Gus Wiseman_, Jun 20 2018