The V-trominoes must line up with the squares on the grid (skew placements are not allowed).
a(n) is the independent domination number of a graph with one node per tromino and an edge for each pair of trominoes that conflict. - Rob Pratt, Oct 02 2019
Table of n, a(n) for n=1..15.
Juris Cernenoks, Illustration of initial terms
Erich Friedman, Problem of the Month (June 2000)
Sequence in context: A056829 A211536 A071764 * A290743 A059291 A177339
Adjacent sequences: A238378 A238379 A238380 * A238382 A238383 A238384
Juris Cernenoks, Feb 25 2014
a(13)-a(15) from Rob Pratt, Oct 02 2019