A065953 Denominator of (-1)^n*n!*(E(n,2)-E(n,1)*E(n-1,1)) where E(n,x) = Sum_{k=0..n} (-1)^k*x^k/k!.

1, 1, 1, 1, 1, 2, 6, 8, 40, 720, 560, 4480, 362880, 1209600, 13305600, 479001600, 188697600, 2641766400, 1307674368000, 774918144000, 1197600768000, 44771844096000, 3119105138688000, 73724303278080000, 4644631106519040000, 374666909259202560000, 8617338912961658880000

Offset

0,6

Links

Table of n, a(n) for n=0..26.

Example

1, 1, 2, 3, 5, 17/2, 89/6, 211/8, 1903/40, 62473/720, ...

Mathematica

e[n_, x_]:=Sum[(-x)^k/k!, {k, 0, n}]; a[n_]:=Denominator[(-1)^n*n!*(e[n, 2]-e[n, 1]e[n-1, 1])]; Array[a, 27, 0] (* Stefano Spezia, Apr 12 2024 *)

Crossrefs

Cf. A065952 (numerator), A065954, A065955, A065956.

Sequence in context: A337882 A095239 A192009 * A371832 A118211 A050552

Adjacent sequences: A065950 A065951 A065952 * A065954 A065955 A065956

Keyword

nonn,frac,changed

Author

N. J. A. Sloane, Dec 08 2001

Extensions

a(0)=1 prepended by and a(25)-a(26) from Stefano Spezia, Apr 12 2024

Status

approved