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A105630 Column 0 of triangle A105629, which is the matrix logarithm of triangle A105623. 1
0, 1, 3, 17, 135, 1353, 16251, 226857, 3605775, 64288209, 1270969971, 27603549057, 653517822615, 16755529944729, 462601460800491, 13685474246611737, 431948067953729055, 14489465807596684449, 514794897939436455651 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

A105623 equals the matrix square-root of triangle A105615.

LINKS

Table of n, a(n) for n=0..18.

PROG

(PARI) {a(n)=local(L, M=matrix(n+1, n+1, 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)))))^-1); L=sum(i=1, #M, (-1)^(i-1)*(M-M^0)^i/i); return(if(n<0, 0, L[n+1, 1]/2))}

CROSSREFS

Cf. A105629, A105623, A105615.

Sequence in context: A093986 A192459 A055214 * A199138 A006290 A060003

Adjacent sequences:  A105627 A105628 A105629 * A105631 A105632 A105633

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Apr 16 2005

STATUS

approved

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Last modified September 24 03:21 EDT 2020. Contains 337315 sequences. (Running on oeis4.)