A025973 Expansion of 1/((1-2*x)*(1-4*x)*(1-7*x)*(1-10*x)).

1, 23, 349, 4443, 51597, 568155, 6054973, 63196331, 650620333, 6637326267, 67293219357, 679380276939, 6838972903309, 68706054180059, 689275354683901, 6908259384473067, 69191143298038125, 692671313513140731, 6932032436299415005, 69357560020925493515, 693836252013796546381

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (23,-180,556,-560).

Formula

a(n) = (5*10^(n+3)-16*7^(n+3)+20*4^(n+3)-9*2^(n+3))/720. - Yahia Kahloune, May 23 2013

a(n) = (4^(n+1)-2^(n+1))/2+17*a(n-1)-70*a(n-2). - Vincenzo Librandi, Jun 22 2026

Mathematica

a[0]=1; a[1]=23; Do[a[n]=(4^(n+1)-2^(n+1))/2+17*a[n-1]-70*a[n-2], {n, 2, 22}]; Table[a[n], {n, 0, 20}] (* Vincenzo Librandi, Jun 22 2026 *)

Prog

(Magma) I:=[1, 23]; [n le 2 select I[n] else (4^n-2^n)/2+17*Self(n-1)-70*Self(n-2): n in [1..21]]; // Vincenzo Librandi, Jun 22 2026

Crossrefs

Sequence in context: A125480 A023950 A268465 * A277833 A022469 A028030

Adjacent sequences: A025970 A025971 A025972 * A025974 A025975 A025976

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

a(18)-a(20) from Vincenzo Librandi, Jun 22 2026

Status

approved