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A101126 Diagonal sums of a Chebyshev number triangle. 1
1, 0, 0, 1, 3, 3, 8, 30, 117, 466, 1960, 8655, 40391, 200085, 1051888, 5844844, 34131049, 208344660, 1324262256, 8743620525, 59891078347, 425216195191, 3126418416440, 23778261543210, 186815245299549, 1513931016854598 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

Diagonal sums of number triangle A101124.

LINKS

Index entries for sequences related to Chebyshev polynomials.

FORMULA

a(n)=sum{k=0..floor(n/2), if(k<n-k, T(n-2k, k), if(k=n-k, 1, 0))} where T(n, k)=(n/2)sum{j=0..floor(n/2), C(n-j, j)(-1)^j*(2k)^(n-2j)}.

CROSSREFS

Sequence in context: A190659 A202536 A038068 * A119006 A109695 A010610

Adjacent sequences:  A101123 A101124 A101125 * A101127 A101128 A101129

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Dec 02 2004

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Last modified February 14 10:24 EST 2012. Contains 205614 sequences.