OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
J. P. McSorley, Counting structures in the Möbius ladder, Discrete Math., 184 (1998), 137-164.
Eric Weisstein's World of Mathematics, Hamiltonian Path
Eric Weisstein's World of Mathematics, Möbius Ladder
Index entries for linear recurrences with constant coefficients, signature (2,1,-4,1,2,-1).
FORMULA
If n is even, a(n) = n^3+2*n, else a(n) = n^3+3*n.
G.f.: 4*x*(x^2+1)*(x^2+x+1) / ((x-1)^4*(x+1)^2). - Colin Barker, Apr 05 2013
MAPLE
MATHEMATICA
CoefficientList[Series[4 x (x^2 + 1) (x^2 + x + 1)/((x - 1)^4 (x + 1)^2), {x, 0, 50}], x] (* Vincenzo Librandi, Oct 16 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved