OFFSET
0,1
COMMENTS
Sequence extrapolated to n=0 using recurrence. - Andrew Howroyd, May 15 2017
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..860 (terms 0..200 from Andrew Howroyd)
Eric Weisstein's World of Mathematics, Antiprism Graph
Eric Weisstein's World of Mathematics, Edge Cover
Index entries for linear recurrences with constant coefficients, signature (13,18,1,-4).
FORMULA
From Andrew Howroyd, May 15 2017 (Start)
a(n) = 13*a(n-1)+18*a(n-2)+a(n-3)-4*a(n-4) for n>=4.
G.f.: (-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1).
(End)
MATHEMATICA
Table[RootSum[4 - # - 18 #^2 - 13 #^3 + #^4 &, #^n &], {n, 0, 20}] (* Eric W. Weisstein, May 17 2017 *)
LinearRecurrence[{13, 18, 1, -4}, {13, 205, 2902, 41413}, {0, 20}] (* Eric W. Weisstein, May 17 2017 *)
CoefficientList[Series[(-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1), {x, 0, 50}], x]
PROG
(PARI)
Vec((-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1)+O(x^20)) \\ Andrew Howroyd, May 15 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Apr 01 2017
EXTENSIONS
a(0)-a(2) and a(9)-a(18) from Andrew Howroyd, May 15 2017
STATUS
approved