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,-191,564,-540).
FORMULA
a(n) = -2^n/7+9*3^n/14-243*9^n/14+125*10^n/7. - R. J. Mathar, Jun 20 2013
a(n) = 3^(n+1)-2^(n+1)+19*a(n-1)-90*a(n-2). - Vincenzo Librandi, May 17 2026
MATHEMATICA
CoefficientList[Series[1/((1-2x)(1-3x)(1-9x)(1-10x)), {x, 0, 20}], x] (* Harvey P. Dale, Dec 31 2021 *)
(* Alternative: *)
LinearRecurrence[{24, -191, 564, -540}, {1, 24, 385, 5220}, 20] (* Harvey P. Dale, Dec 31 2021 *)
(* Alternative: *)
a[0]=1; a[1]=24; a[n_]:=a[n]=3^(n+1)-2^(n+1)+19*a[n-1]-90*a[n-2]; Table[a[n], {n, 0, 25}] (* Vincenzo Librandi, May 17 2026 *)
PROG
(Magma) I:=[1, 24]; [n le 2 select I[n] else 3^n-2^n+19*Self(n-1)-90*Self(n-2): n in [1..22]]; // Vincenzo Librandi, May 17 2026
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, May 17 2026
STATUS
approved
