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A117178 Riordan array (c(x^2)/sqrt(1-4x^2),xc(x^2)), c(x) the g.f. of A000108. +0
2
1, 0, 1, 3, 0, 1, 0, 4, 0, 1, 10, 0, 5, 0, 1, 0, 15, 0, 6, 0, 1, 35, 0, 21, 0, 7, 0, 1, 0, 56, 0, 28, 0, 8, 0, 1, 126, 0, 84, 0, 36, 0, 9, 0, 1, 0, 210, 0, 120, 0, 45, 0, 10, 0, 1, 462, 0, 330, 0, 165, 0, 55, 0, 11, 0, 1, 0, 792, 0, 495, 0, 220, 0, 66, 0, 12, 0, 1, 1716, 0, 1287, 0, 715, 0 (list; table; graph; listen)
OFFSET

0,4

COMMENT

Row sums are A058622(n+1). Diagonal sums are A001791(n+1), with interpolated zeros. Inverse is A117179.

FORMULA

Number triangle T(n,k)=C(n+1,(n-k)/2)(1+(-1)^(n-k))/2; Column k has e.g.f. Bessel_I(k,2x)+Bessel_I(k+2,2x).

EXAMPLE

Triangle begins

1,

0, 1,

3, 0, 1,

0, 4, 0, 1,

10, 0, 5, 0, 1,

0, 15, 0, 6, 0, 1,

35, 0, 21, 0, 7, 0, 1,

0, 56, 0, 28, 0, 8, 0, 1,

126,0, 84, 0, 36, 0, 9, 0, 1

CROSSREFS

Sequence in context: A049769 A117179 A111526 this_sequence A111527 A035695 A100257

Adjacent sequences: A117175 A117176 A117177 this_sequence A117179 A117180 A117181

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Mar 01 2006

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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