A025947 Expansion of 1/((1-2*x)*(1-3*x)*(1-7*x)*(1-12*x)).

1, 24, 391, 5478, 71449, 898044, 11063179, 134771010, 1631361325, 19675158360, 236793832639, 2846370045246, 34190350504129, 410521580544372, 4927920602312371, 59146678721188986, 709841565237360661, 8518668727317136080, 102228014340249027175, 1226764099373577821430, 14721364683527518580521

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (24,-185,534,-504).

Formula

a(n) = -7^(n+3)/100 +96*12^n/25+3^(n+1)/4-2^(n+2)/25. - R. J. Mathar, May 22 2013

a(n) = 3^(n+1)-2^(n+1)+19*a(n-1)-84*a(n-2). - Vincenzo Librandi, May 12 2026

Mathematica

a[0]=1; a[1]=24; a[n_]:=a[n]=3^(n+1)-2^(n+1)+19*a[n-1]-84*a[n-2]; Table[a[n], {n, 0, 21}] (* Vincenzo Librandi, May 12 2026 *)

Prog

(Magma) I:=[1, 24]; [n le 2 select I[n] else 3^n-2^n+19*Self(n-1)-84*Self(n-2): n in [1..21]]; // Vincenzo Librandi, May 12 2026

Crossrefs

Sequence in context: A020494 A020573 A022448 * A007752 A145602 A020447

Adjacent sequences: A025944 A025945 A025946 * A025948 A025949 A025950

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Vincenzo Librandi, May 12 2026

Status

approved