%I

%S 1,1,1,2,2,5,5,12,13,30,36,80,97,213,266,578,737,1589,2051,4408,5747,

%T 12333,16213,34737,45979,98367,131007,279902

%N Triangular polyominoes (n-iamonds) with bilateral symmetry (holes are allowed).

%Y Cf. A000577, A006534, A030223, A030224.

%K nonn

%O 1,4

%A _David W. Wilson_

%E a(19) to a(28) from _Joseph Myers_, Sep 24 2002