Triangular array that counts rooted polyominoes.

Terms

a(0) =1a(1) =2a(2) =1a(3) =5a(4) =3a(5) =1a(6) =13a(7) =9a(8) =4a(9) =1a(10) =35a(11) =26a(12) =14a(13) =5a(14) =1a(15) =96a(16) =75a(17) =45a(18) =20a(19) =6a(20) =1a(21) =267a(22) =216a(23) =140a(24) =71a(25) =27a(26) =7a(27) =1a(28) =750a(29) =623