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 A174122 #2 Mar 30 2012 18:40:51 %S A174122 1,2,5,18,105,946,12589,240482,6526289,250119330,13512676053, %T A174122 1027978959346,110155994874553,16631509898085074,3540687511804739837, %U A174122 1063409634646294541250,450894476653951603096737 %N A174122 Partial sums of A001831. %C A174122 Partial sums of number of labeled graded partially ordered sets with n elements. The subsequence of primes in this partial sum begins: 2, 5, 12589. %F A174122 a(n) = SUM[i=0..n] A001831(i) = SUM[i=0..n] SUM[j=0..i] ((-1)^j*C(n,j)*A047863(j)). %Y A174122 Cf. A001831, A002031, A047863, A052332, A001833, A048194, A052296, A135753, A135754. %K A174122 nonn %O A174122 0,2 %A A174122 _Jonathan Vos Post_, Mar 08 2010