OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Clique Covering Number
Eric Weisstein's World of Mathematics, Sierpinski Tetrahedron Graph
Index entries for linear recurrences with constant coefficients, signature (5,-4).
FORMULA
a(n) = A199209(n-2) = 10*4^(n-3) for n >= 3.
From Colin Barker, Jul 20 2019: (Start)
G.f.: x*(1 + 2*x)*(1 - 3*x + x^2) / ((1 - x)*(1 - 4*x)).
a(n) = 5*a(n-1) - 4*a(n-2) for n>4.
(End)
PROG
(PARI) Vec(x*(1 + 2*x)*(1 - 3*x + x^2) / ((1 - x)*(1 - 4*x)) + O(x^30)) \\ Colin Barker, Jul 20 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Apr 22 2019
EXTENSIONS
More terms from Colin Barker, Jul 20 2019
STATUS
approved