A141047 - OEIS

A141047

Numerators of A091137(n)*T(n,n)/n! where T(i,j)=Integral (x= i.. i+1) x*(x-1)*(x-2)* .. *(x-j+1) dx.

1, 3, 23, 55, 1901, 4277, 198721, 434241, 14097247, 30277247, 2132509567, 4527766399, 13064406523627, 27511554976875, 173233498598849, 362555126427073, 192996103681340479, 401972381695456831, 333374427829017307697, 691668239157222107697, 236387355420350878139797

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OFFSET

0,2

COMMENTS

Numerators of the main diagonal of the array A091137(j)*T(i,j)/j! where T(i,j)=Integral (x= i.. i+1) x*(x-1)*(x-2)* .. *(x-j+1) dx.

The reduced fractions of the array T(i,j) are shown in A140825, which also describes how the integrand is a generating function of Stirling numbers.

The sequence A027760 plays a role i) in relating to A091137 as described there and

ii) in a(n+1)-A027760(n+1)*a(n)= A002657(n+1), numerators of the diagonal T(n,n+1).

REFERENCES

P. Curtz, Integration numerique des systemes differentiels a conditions initiales. Note 12, Centre de Calcul Scientifique de l' Armement, Arcueil (1969), p. 36.

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) = numerator( A091137(n)*T(n,n)/n!) where T(n,n) = sum_{k=0..n} A048994(n,k)*((n+1)^(k+1)-n^(k+1))/(k+1).

MAPLE

T := proc(i, j) local var, k ; var := x ; for k from 1 to j-1 do var := var*(x-k) ; od: int(var, x=i..i+1) ; simplify(A091137(j)*%/j!) ; numer(%) ; end:

A141047 := proc(n) T(n, n) ; end: for n from 0 to 20 do printf("%a, ", A141047(n) ) ; od: # R. J. Mathar, Feb 23 2009

MATHEMATICA

b[n_] := b[n] = (* A091137 *) If[n==0, 1, Product[d, {d, Select[Divisors[n] + 1, PrimeQ]}]*b[n-1]]; T[i_, j_] := Integrate[Product[x-k, {k, 0, j-1}], {x, i, i+1}]; a[n_] := b[n]*T[n, n]/n!; Table[a[n] // Numerator, {n, 0, 20}] (* Jean-François Alcover, Jan 10 2016 *)

CROSSREFS

Cf. A140811, A140825, A141045.

Sequence in context: A181422 A082244 A232193 * A196538 A216418 A254626

Adjacent sequences: A141044 A141045 A141046 * A141048 A141049 A141050

KEYWORD

nonn

AUTHOR

Paul Curtz, Jul 31 2008

EXTENSIONS

Edited and extended by R. J. Mathar, Feb 23 2009

STATUS

approved