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

1,2

Links

Table of n, a(n) for n=1..64.

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

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

Mathematica

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

Crossrefs

Sequence in context: A336874 A040120 A365220 * A336904 A051309 A077344

Adjacent sequences: A176589 A176590 A176591 * A176593 A176594 A176595

Keyword

nonn,tabf

Author

Vincenzo Librandi, Apr 23 2010

Extensions

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

Status

approved