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A023043
6th differences of factorial numbers.
12
265, 2119, 18806, 183822, 1965624, 22852200, 287250480, 3884393520, 56255149440, 869007242880, 14266826784000, 248112809683200, 4557208289356800, 88166812070937600, 1792259345728051200, 38195370237024000000, 851609625265631232000, 19827505082582765568000
OFFSET
0,1
FORMULA
From Vaclav Kotesovec, Oct 21 2012: (Start)
E.g.f.: (265 + 264*x + 135*x^2 + 40*x^3 + 15*x^4 + x^6)/(1-x)^7.
D-finite Recurrence: a(n) = (n+7)*a(n-1) - (n-1)*a(n-2), n>=1.
a(n) ~ n!*n^6. (End)
a(n) = (n^6 + 15*n^5 + 100*n^4 + 355*n^3 + 694*n^2 + 689*n + 265) * n!. - Christian Krause, May 03 2026
MATHEMATICA
CoefficientList[Series[-(265 + 264x + 135x^2 + 40x^3 + 15x^4 + x^6)/(x - 1)^7, {x, 0, 20}], x] Range[0, 20]! (* Vaclav Kotesovec, Oct 21 2012 *)
(* Alternative: *)
Differences[Range[0, 23]!, 6] (* Alonso del Arte, Nov 10 2018 *)
PROG
(PARI) my(x='x+O('x^66)); Vec(serlaplace( -(265 +264*x +135*x^2 +40*x^3 +15*x^4 +x^6) / (x-1)^7 )) \\ Joerg Arndt, May 04 2013
(GAP) a:=[265, 2119];; for n in [3..20] do a[n]:=(n+6)*a[n-1]-(n-2)*a[n-2]; od; a; # Muniru A Asiru, Nov 23 2018
(Magma) I:=[2119, 18806]; [265] cat [n le 2 select I[n] else (n+7)*Self(n-1) - (n-1)*Self(n-2): n in [1..30]]; // G. C. Greubel, Nov 23 2018
(SageMath)
f= (265 + 264*x + 135*x^2 + 40*x^3 + 15*x^4 + x^6)/(1-x)^7
g=f.taylor(x, 0, 30)
L=g.coefficients()
coeffs={c[1]:c[0]*factorial(c[1]) for c in L}
coeffs # G. C. Greubel, Nov 23 2018
CROSSREFS
KEYWORD
nonn,easy
STATUS
approved