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A101125
Row sums of a Chebyshev number triangle.
4
1, 1, 1, 4, 13, 49, 233, 1240, 7201, 45521, 311225, 2285116, 17909309, 149080865, 1312597361, 12180044528, 118740086369, 1212695223137, 12942512039697, 144018843991220, 1667526171728525, 20053044685823697, 250043383489271193
OFFSET
0,4
COMMENTS
Row sums of A101124.
FORMULA
a(n)=sum{k=0..n, if(k<n, T(n-k, k), if(k=n, 1, 0))} where T(n, k)=(n/2)sum{j=0..floor(n/2), C(n-j, j)(-1)^j*(2k)^(n-2j)}.
MATHEMATICA
Table[Sum[ChebyshevT[k, n-k], {k, 0, n}], {n, 0, 30}] (* Vaclav Kotesovec, Jan 20 2019 *)
PROG
(PARI) {a(n) = sum(k=0, n, polchebyshev(k, 1, n-k))} \\ Seiichi Manyama, Jan 20 2019
CROSSREFS
Sequence in context: A140660 A149453 A149454 * A284336 A230081 A364907
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Dec 02 2004
STATUS
approved