A007808 - cp's OEIS frontend

A007808 Number of directed column-convex polyominoes of height n: a(k+1)=(k+1)*a(k)+(a(1)+...+a(k)).

n	a(n)
0	1
1	1
2	3
3	13
4	69
5	431
6	3103
7	25341
8	231689
9	2345851
10	26065011
11	315386633
12	4128697741
13	58145826519
14	876660153671
15	14089181041141
16	240455356435473
17	4343224875615731
18	82776756452911579
19	1660133837750060001
20	34950186057896000021
21	770651602576606800463

[1, 1, 3, 13, 69, 431, 3103, 25341, 231689, 2345851, 26065011, 315386633, 4128697741, 58145826519, 876660153671, 14089181041141, 240455356435473, 4343224875615731, 82776756452911579, 1660133837750060001, 34950186057896000021, 770651602576606800463]

cp's OEIS Frontend

A007808 Number of directed column-convex polyominoes of height n: a(k+1)=(k+1)*a(k)+(a(1)+...+a(k)).

Table of values

List of values