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A158838 Column 2 of triangle A158835. 4
1, 3, 21, 217, 2904, 47337, 906557, 19910808, 492818850, 13564326950, 410807572044, 13573135469214, 485765085176420, 18717987193565613, 772565258231236269, 34002334709760133807, 1589555183231724515700 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Triangle A158835 transforms diagonals in the array A158825 of coefficients of successive iterations of x*C(x) where C(x) is the Catalan function (A000108).

LINKS

Table of n, a(n) for n=0..16.

PROG

(PARI) {a(n)=local(F=x, CAT=serreverse(x-x^2+x*O(x^(n+4))), M, N, P); M=matrix(n+4, n+4, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, CAT)); polcoeff(F, c)); N=matrix(n+3, n+3, r, c, M[r, c]); P=matrix(n+3, n+3, r, c, M[r+1, c]); (P~*N~^-1)[n+3, 3]}

CROSSREFS

Cf. A158835, A158836, A158837, A158839, A158840.

Sequence in context: A291743 A120972 A168479 * A236963 A107716 A032033

Adjacent sequences:  A158835 A158836 A158837 * A158839 A158840 A158841

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Mar 28 2009

STATUS

approved

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Last modified January 24 16:34 EST 2020. Contains 331207 sequences. (Running on oeis4.)