OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..194
Wikipedia, Chebyshev polynomials.
FORMULA
a(n) = U_{n-1}(2*n^2-1).
a(n) = (1/2) * Sum_{k=0..n-1} binomial(2*n,2*k+1)*(n^2-1)^(n-1-k)*n^(2*k).
a(n) ~ 2^(2*n - 2) * n^(2*n - 2). - Vaclav Kotesovec, Jan 07 2019
MATHEMATICA
Table[ChebyshevU[2*n - 1, n]/(2*n), {n, 1, 15}] (* Vaclav Kotesovec, Jan 07 2019 *)
PROG
(PARI) {a(n) = polchebyshev(2*n-1, 2, n)/(2*n)}
(PARI) {a(n) = polchebyshev(n-1, 2, 2*n^2-1)}
(PARI) {a(n) = sum(k=0, n-1, binomial(2*n, 2*k+1)*(n^2-1)^(n-1-k)*n^(2*k))/2}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 06 2019
STATUS
approved