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 A131250 #12 Feb 18 2022 22:38:29 %S A131250 1,2,1,4,4,1,8,11,6,1,16,26,22,8,1,32,57,64,37,10,1,64,120,163,130,56, %T A131250 12,1,128,247,382,386,232,79,14,1,256,502,848,1024,794,378,106,16,1, %U A131250 512,1013,1816,2510,2380,1471,576,137,18,1 %N A131250 A007318 * A004070. %C A131250 Row sums = A061667: (1, 3, 9, 26, 73, 201, ...). %C A131250 Companion triangle = A131249 = A007318 * A052509, where A052509 is the reversal of A004070. %C A131250 Reversal of A097750. - _Philippe Deléham_, Jan 11 2014 %C A131250 Riordan array (1/(1-2x), x/(1-x)^2). - _Philippe Deléham_, Jan 11 2014 %C A131250 Diagonal sums are A045623. - _Philippe Deléham_, Jan 11 2014 %H A131250 Filippo Disanto, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Disanto/disanto5.html">Some Statistics on the Hypercubes of Catalan Permutations</a>, Journal of Integer Sequences, Vol. 18 (2015), Article 15.2.2 (see Table 2). %F A131250 Binomial transform of A004070. %F A131250 T(n,k) = 2*T(n-1,k) + T(n-1,k-1) - T(n-2,k), T(0,0)=1, T(n,k)=0 if k < 0 or if k > n. - _Philippe Deléham_, Jan 11 2014 %e A131250 First few rows of the triangle: %e A131250 1; %e A131250 2, 1; %e A131250 4, 4, 1; %e A131250 8, 11, 6, 1; %e A131250 16, 26, 22, 8, 1; %e A131250 32, 57, 64, 37, 10, 1; %e A131250 ... %Y A131250 Cf. A004070, A061667, A131249, A007318. %K A131250 nonn,tabl %O A131250 0,2 %A A131250 _Gary W. Adamson_, Jun 23 2007 %E A131250 More terms from _Philippe Deléham_, Jan 11 2014