OFFSET
1,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..19
Eric Weisstein's World of Mathematics, Total Dominating Set
Eric Weisstein's World of Mathematics, Triangular Grid Graph
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Apr 17 2018
EXTENSIONS
Terms a(6) and beyond from Andrew Howroyd, Apr 17 2018
STATUS
approved