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 A102223 #9 Jul 12 2015 19:59:21 %S A102223 0,1,3,22,323,7906,290262,14919430,1022475715,90094491994, %T A102223 9923239949978,1335853771297750,215797095378591542, %U A102223 41198645313603207990,9176288655853717238830,2358300288047799986966722 %N A102223 Column 0 of triangular matrix A102222, which equals -log[2*I - A008459]. %C A102223 Triangle A008459 consists of squared binomial coefficients. %F A102223 a(n) = 1 + (1/n)*Sum_{k=0..n-1} C(n, k)^2*k*a(k) for n>0, with a(0)=0. %F A102223 Sum_{n>=0} a(n)*x^n/n!^2 = -log(2-BesselI(0,2*sqrt(x))). - _Vladeta Jovovic_, Jul 16 2006 %e A102223 a(2) = 3 = 1 + (1*0*0 + 4*1*1)/2, %e A102223 a(3) = 22 = 1 + (1*0*0 + 9*1*1 + 9*2*3)/3, %e A102223 a(4) = 323 = 1 + (1*0*0 + 16*1*1 + 36*2*3 + 16*3*22)/4, %e A102223 a(5) = 7906 = 1 + (1*0*0 + 25*1*1 + 100*2*3 + 100*3*22 + 25*4*323)/5. %o A102223 (PARI) a(n)=if(n<1,0,1+sum(k=0,n-1,binomial(n,k)^2*k*a(k))/n) %Y A102223 Cf. A008459, A102220, A102222. %K A102223 nonn %O A102223 0,3 %A A102223 _Paul D. Hanna_, Dec 31 2004