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A318192
a(n) = U_{n}(n)/(n+1) where U_{n}(x) is a Chebyshev polynomial of the second kind.
2
1, 1, 5, 51, 781, 16005, 411881, 12776743, 464278585, 19350109449, 910126036909, 47694593157211, 2755988277318277, 174100457124362509, 11937317942278298961, 882942450221936166735, 70077737629245663437041, 5940877531422707027770385
OFFSET
0,3
LINKS
FORMULA
a(n) = A323118(n)/(n+1).
a(n) = Sum_{k=0..floor(n/2)} (1/(2*k+1)) * binomial(n,2*k)*(n^2-1)^k*n^(n-2*k).
PROG
(PARI) {a(n) = polchebyshev(n, 2, n)/(n+1)}
(PARI) {a(n) = sum(k=0, n\2, binomial(n, 2*k)*(n^2-1)^k*n^(n-2*k)/(2*k+1))}
CROSSREFS
Cf. A323118.
Sequence in context: A339234 A187235 A343674 * A343687 A299435 A095839
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 07 2019
STATUS
approved