1,1

Table of n, a(n) for n=1..9.

Eric Weisstein's World of Mathematics, Total Dominating Set

Eric Weisstein's World of Mathematics, Triangular Grid Graph

Sequence in context: A180754 A224091 A224751 * A255355 A201133 A036114

Adjacent sequences: A303225 A303226 A303227 * A303229 A303230 A303231

nonn,more

Eric W. Weisstein, Apr 20 2018

a(7)-a(10) from Andrew Howroyd, Apr 20 2018

approved