A136229 Column 1 of triangle A136228; also equals column 3 of square array A136217.

1, 4, 24, 198, 2116, 28052, 446560, 8325700, 178284892, 4317391240, 116757568072, 3489919886180, 114304360656596, 4072431454706374, 156845310426959972, 6494800764749659199, 287796117221639178946, 13590112496057829388516

Offset: 0

Author

Paul D. Hanna, Jan 28 2008

Keywords

• nonn

Crossrefs

Cf. A136228, A136217; A136221.

Programs

PARI

{a(n)=local(P=Mat(1),U=Mat([1,0;1,1]),PShR);if(n>0,for(i=0,n+1, PShR=matrix(#P,#P, r,c, if(r>=c,if(r==c,1,if(c==1,0,P[r-1,c-1]))));U=P*PShR^2; U=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,U[r,c], if(c==1,(P^3)[ #P,1],(P^(3*c-1))[r-c+1,1])))); P=matrix(#U, #U, r,c, if(r>=c, if(r<#R,P[r,c], (U^c)[r-c+1,1])))));U[n+2,2]}