A176593 List of pairs n,13*n.

1, 13, 2, 26, 3, 39, 4, 52, 5, 65, 6, 78, 7, 91, 8, 104, 9, 117, 10, 130, 11, 143, 12, 156, 13, 169, 14, 182, 15, 195, 16, 208, 17, 221, 18, 234, 19, 247, 20, 260, 21, 273, 22, 286, 23, 299, 24, 312, 25, 325, 26, 338, 27, 351, 28, 364, 29, 377, 30, 390, 31, 403, 32, 416, 33

Offset: 1

Author

Vincenzo Librandi, Apr 23 2010

Keywords

• nonn
• tabf
• easy

Links

• Colin Barker, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Crossrefs

Cf. A008595.

Programs

Mathematica

Table[{n,13n},{n,50}]//Flatten (* or *) LinearRecurrence[{0,2,0,-1},{1,13,2,26},100] (* Harvey P. Dale, Oct 16 2019 *)

PARI

Vec(x*(1+13*x) / ((1-x)^2*(1+x)^2) + O(x^30)) \\ Colin Barker, Jan 02 2017

Formula

a(n) = (14*n+12*n*(-1)^n+1 + (-1)^(n-1))/4 for n>1.

From Colin Barker, Jan 02 2017: (Start)

a(n) = 2*a(n-2) - a(n-4) for n>4.

G.f.: x*(1+13*x) / ((1-x)^2*(1+x)^2).

(End)

Extensions

Partially edited by N. J. A. Sloane, Jun 23 2010