A176592 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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