%I #14 Jan 20 2019 16:19:29

%S 1,1,1,4,13,49,233,1240,7201,45521,311225,2285116,17909309,149080865,

%T 1312597361,12180044528,118740086369,1212695223137,12942512039697,

%U 144018843991220,1667526171728525,20053044685823697,250043383489271193

%N Row sums of a Chebyshev number triangle.

%C Row sums of A101124.

%H Seiichi Manyama, <a href="/A101125/b101125.txt">Table of n, a(n) for n = 0..533</a>

%H <a href="/index/Ch#Cheby">Index entries for sequences related to Chebyshev polynomials.</a>

%F 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)}.

%t Table[Sum[ChebyshevT[k, n-k], {k, 0, n}], {n, 0, 30}] (* _Vaclav Kotesovec_, Jan 20 2019 *)

%o (PARI) {a(n) = sum(k=0, n, polchebyshev(k, 1, n-k))} \\ _Seiichi Manyama_, Jan 20 2019

%K easy,nonn

%O 0,4

%A _Paul Barry_, Dec 02 2004