OFFSET
1,2
LINKS
Daniel Starodubtsev, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
FORMULA
a(n) = floor( (7n-5)/2 ). - Santi Spadaro, Jul 24 2001
G.f.: x*(1 + 3*x + 3*x^2) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Dec 04 2011
a(n) = 4n - 3 - floor(n/2). - Wesley Ivan Hurt, Oct 16 2013
E.g.f.: 3 + ((14*x - 11)*exp(x) - exp(-x))/4. - David Lovler, Sep 01 2022
MAPLE
MATHEMATICA
Table[4n-3-Floor[n/2], {n, 100}] (* Wesley Ivan Hurt, Oct 16 2013 *)
PROG
(PARI) a(n) = 4*n-n\2-3; \\ Altug Alkan, Sep 10 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved