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 A226434 #8 Jun 14 2016 10:34:33 %S A226434 0,1,3,10,37,146,595,2456,10167,42027,173201,711397,2912633,11891030, %T A226434 48425597,196790382,798251109,3232928429,13075849791,52825304031, %U A226434 213196622183,859690304703,3463979709111,13948292729231,56132430446203,225778880966297,907726113188331,3647961305524521,14655086058873287,58855311286307572 %N A226434 The number of sum decomposable permutations which avoid the patterns 3124 and 4312. %H A226434 Jay Pantone, <a href="http://arxiv.org/abs/1309.0832">The Enumeration of Permutations Avoiding 3124 and 4312</a>, arXiv:1309.0832 [math.CO], (2013) %F A226434 G.f.: -(8*x^5 - 16*x^4 + 19*x^3 - 8*x^2 - sqrt(-4*x + 1)*(2*x^4 + x^3 - 4*x^2 + x) + x)/(12*x^4 - 31*x^3 + 27*x^2 + sqrt(-4*x + 1)*(4*x^4 - 13*x^3 + 15*x^2 - 7*x + 1) - 9*x + 1) %F A226434 Conjecture: +(95*n+537)*(n+2)*a(n) +(95*n^2-16421*n-14748) *a(n-1) +(-6403*n^2+124495*n-60066) *a(n-2) +(21565*n^2-354883*n+596496) *a(n-3) +2*(-5092*n^2+138877*n-395970) *a(n-4) +8*(-2470*n^2+11113*n+12744) *a(n-5) +192*(38*n-67)*(2*n-13)*a(n-6)=0. - _R. J. Mathar_, Jun 14 2016 %e A226434 Example: a(4)=10 because there are 10 sum decomposable permutations of length 4 which avoid the patterns 3124 and 4312. %K A226434 nonn %O A226434 1,3 %A A226434 _Jay Pantone_, Sep 03 2013