A105628 Row sums of triangle A105626.

1, 4, 25, 208, 2152, 26524, 378700, 6142948, 111593932, 2244992404, 49561796380, 1191625266388, 31001841211852, 867899276874964, 26017959787456060, 831650920910208628, 28237504357447540972, 1014987937635390612724

Offset

0,2

Comments

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

Links

Table of n, a(n) for n=0..17.

Prog

(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])))}

Crossrefs

Cf. A105615, A105626.

Sequence in context: A120955 A061714 A005411 * A332257 A203219 A064299

Adjacent sequences: A105625 A105626 A105627 * A105629 A105630 A105631

Keyword

nonn

Author

Paul D. Hanna, Apr 16 2005

Status

approved