A136631 - OEIS

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A136631

Antidiagonal sums of triangle A136630, omitting antidiagonals of all zeros.

1, 1, 2, 6, 28, 177, 1449, 14869, 185230, 2738962, 47287352, 939759621, 21241309681, 540698975061, 15370957337418, 484433735633218, 16817886069720724, 639545680226171989, 26507567678760284105 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	FORMULA	`a(n) = Sum_{k=0..n} [x^(2n-2k)] Product_{j=0..[k/2]} 1/(1 - (2j + k-2[k/2])^2*x^2).`
	PROG	`(PARI) {a(n)=sum(k=0, n, polcoeff(1/prod(j=0, k\2, 1-(2j+(k%2))^2x^2 +xO(x^(2n-2k))), 2n-2*k))}`
	CROSSREFS	`Cf. A136630, A003724 (row sums of A136630).` `Sequence in context: A088501 A140092 A052809 * A002435 A104018 A100526` `Adjacent sequences: A136628 A136629 A136630 * A136632 A136633 A136634`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna (pauldhanna(AT)juno.com), Jan 14 2008`

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.