A176592 List of pairs n, 11*n.

1, 11, 2, 22, 3, 33, 4, 44, 5, 55, 6, 66, 7, 77, 8, 88, 9, 99, 10, 110, 11, 121, 12, 132, 13, 143, 14, 154, 15, 165, 16, 176, 17, 187, 18, 198, 19, 209, 20, 220, 21, 231, 22, 242, 23, 253, 24, 264, 25, 275, 26, 286, 27, 297, 28, 308, 29, 319, 30, 330, 31, 341, 32, 352

Offset: 1

Author

Vincenzo Librandi, Apr 23 2010

Keywords

• nonn
• tabf
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Programs

Mathematica

Flatten[Table[{n,11n},{n,40}]] (* or *) LinearRecurrence[{0,2,0,-1},{1,11,2,22},80] (* Harvey P. Dale, Nov 25 2015 *)

Formula

a(n) = (1/4)*(12*n+10*n*(-1)^n+1+(-1)^(n-1)) for n > 1, with a(1) = 1. (corrected by Jon E. Schoenfield, Jun 19 2010)

G.f.: x*(1+11*x)/(-1+x^2)^2. - Harvey P. Dale, Jul 27 2021

Extensions

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