%I #5 Jun 13 2017 23:37:40
%S 1,2,3,5,9,19,47,137,465,1819,8123,41077,233473,1480947,10412591,
%T 80634433,683674833,6312152355,63144706755,681317547509,7896054343497,
%U 97919789763075,1294863406981791,18200820837825481,271147632138373601
%N Column 1 of triangle A113983, also a(n) = [A113983^2](n-1,0) + 1.
%o (PARI) a(n)=local(A,B);A=Mat(1);for(m=2,n+2,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==1 || j==i,B[i,j]=1, B[i,j]=A[i-1,j-1]+(A^2)[i-2,j-1]);));A=B);A[n+2,2]
%Y Cf. A113983, A113985 (column 2), A113986 (column 3), A113987 (column 4); A113988 (=A113983^2), A113989.
%K nonn
%O 0,2
%A _Paul D. Hanna_, Nov 12 2005