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 A089882 #9 Nov 27 2019 02:45:18
%S A089882 0,0,0,0,8,16,32,64,128,256,512,1024,768,1536,3072,6144,12288,24576,
%T A089882 16384,32768,65536,131072,262144,524288,1048576,2097152,4194304,
%U A089882 8388608,16777216,33554432,20971520,41943040,83886080,167772160
%N A089882 Number of subsets of {1, ..., n} containing exactly one twin prime pair.
%F A089882 a(n) = ceiling(A089881(n)/2)*2^(n-A089881(n)).
%Y A089882 Cf. A071538, A089827, A089828, A001359, A006512.
%K A089882 nonn
%O A089882 1,5
%A A089882 _Reinhard Zumkeller_, Nov 13 2003