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 A178684 #5 Mar 30 2012 18:40:52
%S A178684 0,0,1,5,18,53,138,332,757,1661,3546,7424,15328,31336,63618,128531,
%T A178684 258811,519956,1042992,2090009,4185231,8377158,16762853,33536516,
%U A178684 67086633,134190278,268401718,536829625,1073691505,2147422558
%N A178684 Partial sums of cardinalities of coalition sets A095941.
%C A178684 Partial sums of number of subsets of {1,2,...,n} such that every number in the set is no larger than the sum of the other numbers in the set. See formula in A095944. The subsequence of primes begins: 5, 53, 757, 2090009, 16762853.
%e A178684 a(9) = 0 + 0 + 1 + 4 + 13 + 35 + 85 + 194 + 425 = 757 is prime.
%Y A178684 Cf. A000009, A002623, A095941, A095944.
%K A178684 nonn,easy
%O A178684 1,4
%A A178684 _Jonathan Vos Post_, Dec 25 2010