Number of horizontally convex n-ominoes in which the top row has exactly 1 square, which is not above the rightmost square in the second row and the rightmost square in the second row is above the leftmost square in the third row.
A049222
Number of horizontally convex n-ominoes in which the top row has exactly 1 square, which is not above the rightmost square in the second row and the rightmost square in the second row is above the leftmost square in the third row.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =13a(6) =41a(7) =130a(8) =415a(9) =1329a(10) =4260a(11) =13657a(12) =43781a(13) =140346a(14) =449891a(15) =1442157a(16) =4622932a(17) =14819125a(18) =47503729a(19) =152276498a(20) =488132887a(21) =1564743865a(22) =5015895108a(23) =16078800033a(24) =51541709869a(25) =165220529546a(26) =529625878779
External references
- oeis: A049222