OFFSET
0,2
FORMULA
EXAMPLE
A(x) = 1 + 8*x + 72*x^2 + 888*x^3 + 16392*x^4 + 479736*x^5 +...
PROG
(PARI) {a(n, q=2)=local(A=Mat(1), B); if(n<0, 0, for(m=1, n+4, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, if(j==1, B[i, j]=(A^q)[i-1, 1], B[i, j]=(A^q)[i-1, j-1])); )); A=B); return(A[n+4, 4]))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 22 2005
STATUS
approved