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 A102230 #8 Jul 19 2024 19:05:11 %S A102230 1,1,1,4,5,1,24,32,9,1,172,236,76,13,1,1360,1896,656,136,17,1,11444, %T A102230 16116,5828,1348,212,21,1,100520,142544,53112,13184,2376,304,25,1, %U A102230 911068,1298524,494364,128924,25436,3804,412,29,1,8457504,12100952 %N A102230 Triangle, read by rows, where each column equals the convolution of A032349 with the prior column, starting with column 0 equal to A032349 shift right. %C A102230 Row sums equal A027307; the self-convolution of the row sums form A032349. Column 0 equals A032349 shift right. Column 1 is A102231. This triangle is a variant of A100326. %F A102230 G.f.: A(x, y) = (1+x*F(x))/(1-x*y*F(x)) where F(x) is the g.f. of A032349 and satisfies F(x) = (1+x*F(x))^2/(1-x*F(x))^2. %e A102230 This triangle is generated by the recurrence: %e A102230 T(n,k) = Sum_{i=0..n-k} T(i+1,0)*T(n-i-1,k-1) for n>k>0, %e A102230 T(n,0) = Sum_{i=0..n-1} (2*i+1)*T(n-1,i) for n>0, with T(0,0)=1. %e A102230 Rows begin: %e A102230 [1], %e A102230 [1,1], %e A102230 [4,5,1], %e A102230 [24,32,9,1], %e A102230 [172,236,76,13,1], %e A102230 [1360,1896,656,136,17,1], %e A102230 [11444,16116,5828,1348,212,21,1], %e A102230 [100520,142544,53112,13184,2376,304,25,1],... %e A102230 Column 0 is formed from the partial sums of the prior row %e A102230 after a term-by-term product with the odd numbers: %e A102230 T(2,0) = 1*T(1,0) + 3*T(1,1) = 1*1 + 3*1 = 4. %e A102230 T(3,0) = 1*T(2,0) + 3*T(2,1) + 5*T(2,2) = 1*4 + 3*5 + 5*1 = 24. %o A102230 (PARI) {T(n,k)=if(n<k||k<0,0,if(n==0,1,if(k==0, sum(i=0,n-1,(2*i+1)*T(n-1,i)), sum(i=0,n-k,T(i+1,0)*T(n-i-1,k-1)));))} %Y A102230 Cf. A032349, A027307, A102231, A100326. %K A102230 nonn,tabl %O A102230 0,4 %A A102230 _Paul D. Hanna_, Jan 01 2005