A101126 Diagonal sums of a Chebyshev number triangle.

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

Offset

0,5

Comments

Diagonal sums of number triangle A101124.

Links

Table of n, a(n) for n=0..25.

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: A038068 A267952 A221773 * A221001 A222093 A221165

Adjacent sequences: A101123 A101124 A101125 * A101127 A101128 A101129

Keyword

easy,nonn

Author

Paul Barry, Dec 02 2004

Status

approved