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A100248 Row sums of the slanted Catalan convolution table A100247. +0
2
1, 2, 10, 79, 777, 8606, 102512, 1282129, 16605538, 220781427, 2995985345, 41325515589, 577713950666, 8166924383923, 116550061698966, 1676836298476274, 24295472856858786, 354190017808427947 (list; graph; listen)
OFFSET

0,2

FORMULA

a(n) = Sum_{k=0..2n} C(n+2*k-[k/2], k)*(n-[k/2])/(n+2*k-[k/2]). G.f. A(x) satisfies: A(x^2) = ((1+x)/(2-x*(1-sqrt(1-4*x)))-(1-x)/(2+x*(1-sqrt(1+4*x))))/x.

PROGRAM

(PARI) {a(n)=sum(k=0, 2*n, polcoeff(((1-sqrt(1-4*z+z^2*O(z^k)))/(2*z))^(n-k\2), k, z))} (PARI) {a(n)=if(n==0, 1, sum(k=0, 2*n, binomial(n+2*k-(k\2), k)*(n-(k\2))/(n+2*k-(k\2))))}

CROSSREFS

Cf. A100247.

Sequence in context: A063170 A098636 A081363 this_sequence A108486 A003578 A048286

Adjacent sequences: A100245 A100246 A100247 this_sequence A100249 A100250 A100251

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Nov 09 2004

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Last modified July 26 23:19 EDT 2008. Contains 142293 sequences.


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