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A124352
Number of directed Hamiltonian paths on the n-antiprism graph.
6
240, 816, 2400, 6480, 16660, 41440, 100836, 241520, 571692, 1340832, 3121456, 7222040, 16622220, 38085312, 86918688, 197677368, 448182640, 1013320480, 2285339532, 5142429512, 11547488652, 25881229248, 57906534100, 129352490384, 288522099360, 642668803056, 1429687270740, 3176714397960
OFFSET
3,1
LINKS
Eric Weisstein's World of Mathematics, Antiprism Graph
Eric Weisstein's World of Mathematics, Hamiltonian Path
FORMULA
Conjectures from Colin Barker, Dec 21 2015: (Start)
a(n) = 5*a(n-1)-6*a(n-2)-4*a(n-3)+7*a(n-4)+5*a(n-5)-5*a(n-6)-3*a(n-7)+a(n-8)+a(n-9) for n>11.
G.f.: 4*x^3*(60-96*x-60*x^2+84*x^3+61*x^4-73*x^5-41*x^6+15*x^7+14*x^8) / ((1-x)^3*(1-x-2*x^2-x^3)^2).
(End)
Equivalent conjecture: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3) -6*a(n-4) -4*a(n-5) -a(n-6) +672*n -1376 -72*n^2 if n>=9. - R. J. Mathar, Jan 25 2016
CROSSREFS
Cf. A124353 (numbers of directed Hamiltonian cycles).
Sequence in context: A202196 A060663 A092000 * A158562 A234728 A234721
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Oct 27 2006
EXTENSIONS
a(6)-a(10) from Eric W. Weisstein, Apr 03 2008
a(11)-a(18) from Eric W. Weisstein, Dec 16 2013
a(19)-a(30) from Andrew Howroyd, Dec 20 2015
STATUS
approved