OFFSET
1,2
LINKS
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
KEYWORD
nonn,tabf
AUTHOR
Vincenzo Librandi, Apr 23 2010
EXTENSIONS
Partially edited by N. J. A. Sloane, Jun 23 2010
STATUS
approved