Number of horizontally convex n-ominoes in which the top row has exactly 1 square.

A049219

Number of horizontally convex n-ominoes in which the top row has exactly 1 square.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =10a(4) =33a(5) =107a(6) =344a(7) =1103a(8) =3535a(9) =11330a(10) =36317a(11) =116415a(12) =373176a(13) =1196243a(14) =3834643a(15) =12292218a(16) =39403561a(17) =126310851a(18) =404898200a(19) =1297929287a(20) =4160602439a(21) =13337099986a(22) =42753000005a(23) =137047709879a(24) =439315949304

External references