OFFSET
0,5
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..5102
Eric Weisstein's World of Mathematics, Hamiltonian path
Wikipedia, Hamiltonian path
Index entries for linear recurrences with constant coefficients, signature (1,3,-2,-1,-1,-3,1,1,3,1,1,0,-2,0,-1)
FORMULA
EXAMPLE
a(1) = 1: 1.
a(2) = 1: 12.
a(3) = 1: 123.
a(4) = 4: 1234, 1432, 2143, 3214.
a(5) = 6: 12345, 12543, 14325, 14523, 32145, 34125.
a(6) = 16: 123456, 123654, 125436, 125634, 143256, 143652, 145236, 145632, 214365, 214563, 321456, 341256, 365214, 412365, 521436, 541236.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Apr 01 2018
STATUS
approved