A130885 a(n) = 3n^3 - 2n^2 + n - 1.

1, 17, 65, 163, 329, 581, 937, 1415, 2033, 2809, 3761, 4907, 6265, 7853, 9689, 11791, 14177, 16865, 19873, 23219, 26921, 30997, 35465, 40343, 45649, 51401, 57617, 64315, 71513, 79229, 87481, 96287, 105665, 115633, 126209, 137411

Offset

1,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

G.f.: x*(1+13*x+3*x^2+x^3)/(-1+x)^4. - R. J. Mathar, Nov 14 2007

a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4). - Vincenzo Librandi, Feb 12 2013

Mathematica

Table[3*n^3 - 2*n^2 + n - 1, {n, 1, 40}] (* Vincenzo Librandi, Feb 12 2013 *)
LinearRecurrence[{4, -6, 4, -1}, {1, 17, 65, 163}, 40] (* Harvey P. Dale, Nov 21 2019 *)

Prog

(Magma) [3*n^3-2*n^2+n-1: n in [1..40]]; // Vincenzo Librandi, Feb 12 2013
(Magma) I:=[1, 17, 65, 163]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Feb 12 2013

Crossrefs

Cf. A084849; A056109; A056105.

Sequence in context: A226685 A108211 A255885 * A036545 A146807 A156570

Adjacent sequences: A130882 A130883 A130884 * A130886 A130887 A130888

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jul 26 2007

Status

approved