A105628 - OEIS

A105628

Row sums of triangle A105626.

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

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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