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