OFFSET
3,1
LINKS
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
a(n) = (-1)^n*n*(-1 + (-1)^n*(5 + 2*n^2)). - Eric W. Weisstein, Dec 16 2013
G.f.: -8*x^3*(3*x^5-5*x^4-5*x^3+10*x^2-9) / ((x-1)^4*(x+1)^2). - Colin Barker, Apr 05 2013
MATHEMATICA
LinearRecurrence[{2, 1, -4, 1, 2, -1}, {72, 144, 280, 456, 728, 1056}, 40] (* Vincenzo Librandi, Feb 22 2016 *)
PROG
(PARI) Vec(-8*x^3*(3*x^5-5*x^4-5*x^3+10*x^2-9)/((x-1)^4*(x+1)^2) + O(x^100)) \\ Colin Barker, Aug 02 2015
(Magma) [(-1)^n*n*(-1+(-1)^n*(5+2*n^2)): n in [3..45]]; // Vincenzo Librandi, Feb 22 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Feb 20 2008
EXTENSIONS
More terms from Colin Barker, Apr 05 2013
STATUS
approved