0,2

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

(PARI) {a(n)=local(R, M=matrix(n+2, n+2, 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, R[n+2, 2]))}

Cf. A105615, A105626.

Adjacent sequences: A105624 A105625 A105626 this_sequence A105628 A105629 A105630

Sequence in context: A005399 A037184 A085457 this_sequence A051578 A052639 A053506

nonn

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