login
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
OFFSET
0,5
COMMENTS
Diagonal sums of number triangle A101124.
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
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Dec 02 2004
STATUS
approved