A107253 a(n) = n^4 - 15*n + 15.

1, 1, 51, 211, 565, 1221, 2311, 3991, 6441, 9865, 14491, 20571, 28381, 38221, 50415, 65311, 83281, 104721, 130051, 159715, 194181, 233941, 279511, 331431, 390265, 456601, 531051, 614251, 706861, 809565, 923071, 1048111, 1185441, 1335841

Offset

1,3

Comments

a(n) == A109009(n) (mod 10). - Michel Marcus, Sep 05 2013

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Formula

G.f.: x*(1-4*x+56*x^2-44*x^3+15*x^4)/(1-x)^5. - Vincenzo Librandi, Sep 06 2013

Example

a(2) = 2^4 - 15*2 + 15 = 1;
a(4) = 4^4 - 15*4 + 15 = 211.

Mathematica

Table[(n^4 - 15 n + 15), {n, 1, 40}] (* Vincenzo Librandi, Sep 06 2013 *)
LinearRecurrence[{5, -10, 10, -5, 1}, {1, 1, 51, 211, 565}, 40] (* Harvey P. Dale, Nov 23 2019 *)

Prog

(PARI) a(n) = n^4 - 15*n + 15; \\ Michel Marcus, Sep 05 2013
(Magma) [n^4 - 15*n + 15: n in [1..40]]; // Vincenzo Librandi, Sep 06 2013

Crossrefs

Sequence in context: A157916 A007264 A158640 * A030535 A201813 A193250

Adjacent sequences: A107250 A107251 A107252 * A107254 A107255 A107256

Keyword

nonn,easy

Author

Andras Erszegi (erszegi.andras(AT)chello.hu), May 14 2005

Extensions

Definition clarified by Ralf Stephan, Nov 18 2010.

Status

approved