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 A115626 #7 Oct 10 2018 06:16:00 %S A115626 1,1,2,4,14,26,107,190,1234,2182,9947,17414,126953,228398,1039404, %T A115626 1857419,19047146,35215110,168364007,307674658,2378963269,4429446046, %U A115626 20237375204,37371654467,410117798653,776233491226,3797821367602 %N A115626 Number of non-squashing partitions of {1,...,n}. %C A115626 A "non-squashing" partition of n is one where n=p_1+p_2+...+p_k with 1 <= p_1 <= p_2 <= ... <= p_k and p_1 + p_2 + ... + p_i <= p_{i+1} for all 1 <= i < k. %H A115626 N. J. A. Sloane and J. A. Sellers, <a href="http://arxiv.org/abs/math/0312418">On non-squashing partitions</a>, arXiv:math/0312418 [math.CO], 2003. %H A115626 N. J. A. Sloane and J. A. Sellers, <a href="http://dx.doi.org/10.1016/j.disc.2004.11.014">On non-squashing partitions</a>, Discrete Math., 294 (2005), 259-274. %F A115626 a(n) = Sum_{i = 0..ceiling(n/2)-1} (binomial(n, i)*a(i)) + [if n is even] binomial(n, n/2)*(a(n/2)-1/2). %t A115626 a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n, i]*a[i], {i, 0, Ceiling[ n/2] - 1}] + If[EvenQ[n], Binomial[n, n/2] (a[n/2] - 1/2), 0]; %t A115626 Table[a[n], {n, 0, 26}] (* _Jean-François Alcover_, Oct 10 2018 *) %Y A115626 Cf. A018819, A115625. %K A115626 nonn %O A115626 0,3 %A A115626 _Christian G. Bower_, Jan 26 2006