0,2

A105626 equals the cube of the matrix square-root of triangle A105615.

(PARI) {a(n)=local(R, M=matrix(n+3, n+3, m, j, if(m>=j, if(m==j, 1, if(m==j+1, -2*j, polcoeff(1/sum(i=0, m-j, (2*i)!/i!/2^i*x^i)+O(x^m), m-j)))))^-3); R=(M+M^0)/2; for(i=1, floor(2*log(n+2)), R=(R+M*R^(-1))/2); return(if(n<0, 0, sum(k=0, n, R[n+1, k+1])))}

Cf. A105615, A105626.

Sequence in context: A120955 A061714 A005411 this_sequence A064299 A038174 A049118

Adjacent sequences: A105625 A105626 A105627 this_sequence A105629 A105630 A105631

nonn

Paul D. Hanna (pauldhanna(AT)juno.com), Apr 16 2005