OFFSET
1,1
COMMENTS
Antiprism graphs are defined for n>=3; sequence extended to n=1 using closed form
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Antiprism Graph
Eric Weisstein's World of Mathematics, Molecular Topological Index
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = 4*n*(n^2 + n + 8).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
G.f.: 8*x*(4*x^2-6*x+5)/(x-1)^4. - Colin Barker, Nov 04 2012
MATHEMATICA
LinearRecurrence[{4, -6, 4, -1}, {40, 112, 240, 448}, 40] (* Harvey P. Dale, Mar 29 2018 *)
PROG
(PARI) a(n) = {4*n*(n^2 + n + 8)} \\ Andrew Howroyd, Apr 18 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jul 10 2011
EXTENSIONS
Terms a(31) and beyond from Andrew Howroyd, Apr 18 2021
STATUS
approved