OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
K. Cameron, Thomason's algorithm for finding a second hamiltonian circuit through a given edge in a cubic graph is exponential on Krawczyk's graphs, Discrete Mathematics (235), 2001, pp. 69-77.
Donald Knuth, The Art of Computer Programming, Pre-fascicle 8a, Hamiltonian paths and cycles, exercise 77, pp. 16, 26-27 (retrieved Feb 22 2020).
Index entries for linear recurrences with constant coefficients, signature (4,-1,0,-1,0,-1).
FORMULA
G.f.: z(1+z)(11+10z+6z^2+4z^3+z^4)/((1-z)(1-3z-2z^2-2z^3-z^4-z^5)).
a(n) = 4*a(n-1) - a(n-2) - a(n-4) - a(n-6) for n>6. - Colin Barker, Feb 22 2020
MATHEMATICA
LinearRecurrence[{4, -1, 0, -1, 0, -1}, {11, 65, 265, 1005, 3749, 13927}, 20] (* Jinyuan Wang, Feb 22 2020 *)
PROG
(PARI) Vec(z*(1+z)*(11+10*z+6*z^2+4*z^3+z^4)/((1-z)*(1-3*z-2*z^2-2*z^3-z^4-z^5)) + O(z^30)) \\ Jinyuan Wang, Feb 22 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Filip Stappers, Feb 22 2020
EXTENSIONS
More terms from Jinyuan Wang, Feb 22 2020
STATUS
approved