OFFSET
1,1
COMMENTS
The 1-crown graph is the 2-empty graph bar K_2 which has a single dominating set and so differs from a(1) = 3. - Eric W. Weisstein, Sep 04 2021
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Crown Graph
Eric Weisstein's World of Mathematics, Dominating Set
Index entries for linear recurrences with constant coefficients, signature (11,-47,101,-116,68,-16).
FORMULA
a(n) = 4^n - 2^n*(n + 2) + n^2 + n + 3.
From Colin Barker, May 19 2017: (Start)
G.f.: x*(3 - 24*x + 81*x^2 - 126*x^3 + 92*x^4 - 32*x^5) / ((1 - x)^3*(1 - 2*x)^2*(1 - 4*x)).
a(n) = 11*a(n-1) - 47*a(n-2) + 101*a(n-3) - 116*a(n-4) + 68*a(n-5) - 16*a(n-6) for n>6.
(End)
MATHEMATICA
Table[4^n - 2^n (n + 2) + n^2 + n + 3, {n, 25}]
LinearRecurrence[{11, -47, 101, -116, 68, -16}, {3, 9, 39, 183, 833, 3629}, 25]
PROG
(PARI) Vec( x*(3 - 24*x + 81*x^2 - 126*x^3 + 92*x^4 - 32*x^5) / ((1 - x)^3*(1 - 2*x)^2*(1 - 4*x)) + O(x^30)) \\ Colin Barker, May 19 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, May 19 2017
STATUS
approved