a(n) = denominator(R(2*n + 1, 2*n + 1, 1)) where R(n, k, x) = Sum_{u=0..k} ( Sum_{j=0..u} x^j * binomial(u, j) * (j + 1)^n ) / (u + 1).

A362999

a(n) = denominator(R(2*n + 1, 2*n + 1, 1)) where R(n, k, x) = Sum_{u=0..k} ( Sum_{j=0..u} x^j * binomial(u, j) * (j + 1)^n ) / (u + 1).

Terms

    a(0) =2a(1) =3a(2) =15a(3) =105a(4) =315a(5) =3465a(6) =45045a(7) =9009a(8) =153153a(9) =14549535a(10) =14549535a(11) =19684665a(12) =1673196525a(13) =5019589575a(14) =145568097675a(19) =316824683175

External references