A065952 - OEIS

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A065952

Numerator 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, 2, 3, 5, 17, 89, 211, 1903, 62473, 89393, 1324937, 199986173, 1248315547, 25821989299, 1754517215113, 1308752009069, 34794177047129, 32791050165840089, 37082480057069939, 109598046569166901, 7850794626671440751, 1049848025022301180127, 47709314255406993620857

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..23.

EXAMPLE

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

MAPLE

E := proc(n, x) add((-1)^k*x^k/k!, k=0..n); end; f := n -> (-1)^n*n!*(E(n, 2)-E(n, 1)*E(n-1, 1));

MATHEMATICA

e[n_, x_]:=Sum[(-x)^k/k!, {k, 0, n}]; a[n_]:=Numerator[(-1)^n*n!*(e[n, 2]-e[n, 1]e[n-1, 1])]; Array[a, 24, 0] (* Stefano Spezia, Apr 12 2024 *)

CROSSREFS