OFFSET
3,1
LINKS
Eric Weisstein's World of Mathematics, Hamiltonian Cycle.
Eric Weisstein's World of Mathematics, Prism Graph.
Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
FORMULA
a(n) = 2*n + (1-(n mod 2))*4.
From Colin Barker, Aug 22 2012: (Start)
a(n) = a(n-1)+a(n-2)-a(n-3).
G.f.: 2*x^3*(3+3*x-4*x^2)/((1-x)^2*(1+x)). (End)
a(n) = 2*A014681(n+1). - R. J. Mathar, Jan 25 2016
E.g.f.: 2*(2 + x)*cosh(x) + 2*x*sinh(x) - 2*(2 + x + 2*x^2). - Stefano Spezia, Jan 28 2024
MAPLE
seq( 2*n + (1-(n mod 2))*4, n=3..100); # Robert Israel, Mar 14 2016
MATHEMATICA
Table[2 n + (1 - Mod[n, 2]) 4, {n, 3, 100}] (* Vincenzo Librandi, Jan 26 2016 *)
PROG
(Magma) [2*n+(1-(n mod 2))*4: n in [3..80]]; // Vincenzo Librandi, Jan 26 2016
(PARI) Vec(2*x^3*(3+3*x-4*x^2)/((1-x)^2*(1+x)) + O(x^100)) \\ Altug Alkan, Mar 14 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Oct 26 2006
EXTENSIONS
Name clarified by Andrew Howroyd, Mar 14 2016
STATUS
approved