OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
From G. C. Greubel, Oct 12 2019: (Start)
G.f.: (-1 + 12*x + 5*x^2)/(1-x)^3.
E.g.f.: (-1 + 10*x + 8*x^2)*exp(x). (End)
Sum_{n>=0} 1/a(n) = -2/3 +log(2)/6-Pi/12 = -0.81294152437.. - R. J. Mathar, May 07 2024
MAPLE
seq((2*n+1)*(4*n-1), n=0..50); # G. C. Greubel, Oct 12 2019
MATHEMATICA
Table[(2*n+1)*(4*n-1), {n, 0, 50}] (* G. C. Greubel, Oct 12 2019 *)
PROG
(PARI) a(n) = (2*n+1) * (4*n-1); \\ Michel Marcus, Oct 03 2016
(Magma) [(2*n+1)*(4*n-1): n in [0..50]] # G. C. Greubel, Oct 12 2019
(Sage) [(2*n+1)*(4*n-1) for n in range(50)] # G. C. Greubel, Oct 12 2019
(GAP) List([0..50], n-> (2*n+1)*(4*n-1)); # G. C. Greubel, Oct 12 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Terms a(37) onward added by G. C. Greubel, Oct 12 2019
STATUS
approved