OFFSET
1,1
COMMENTS
Extended to a(1)-a(2) using the formula/recurrence.
LINKS
Eric Weisstein's World of Mathematics, Gear Graph
Eric Weisstein's World of Mathematics, Total Dominating Set
Index entries for linear recurrences with constant coefficients, signature (4,2,-13,-6,4).
FORMULA
MATHEMATICA
Table[2 (-1)^n + 2^n LucasL[n] + LucasL[2 n], {n, 20}]
LinearRecurrence[{4, 2, -13, -6, 4}, {3, 21, 48, 161, 473}, 20]
CoefficientList[Series[(-3 - 9 x + 42 x^2 + 34 x^3 - 24 x^4)/(-1 + 4 x + 2 x^2 - 13 x^3 - 6 x^4 + 4 x^5), {x, 0, 20}], x]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, May 02 2018
STATUS
approved