OFFSET
1,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, King Graph
Eric Weisstein's World of Mathematics, Minimum Dominating Set
Index entries for linear recurrences with constant coefficients, signature (0,0,6,0,0,-12,0,0,8).
FORMULA
PROG
(PARI) Vec(2*(1 - x)*(1 + 3*x + 4*x^2 + 6*x^3 - 4*x^5 - 8*x^6 - 4*x^7)/(1 - 2*x^3)^3 + O(x^45))
(PARI) a(n) = {my(t=n\3); 2^t*if(n%3==0, 1, if(n%3==1, t^2 + 5*t + 2, 2*t + 4))}
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Andrew Howroyd, Jan 17 2022
STATUS
approved