A120652 Triangle read by rows: numbers of isomers of unbranched a-4-catapolypentagons.

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 3, 5, 2, 1, 3, 8, 11, 8, 3, 1, 6, 16, 30, 22, 13, 3, 1, 10, 38, 72, 74, 45, 18, 4, 1, 20, 80, 182, 208, 164, 73, 25, 4, 1, 36, 180, 434, 598, 527, 310, 119, 32, 5, 1, 72, 384, 1048, 1600, 1652, 1120, 548, 172, 41, 5, 1

Offset: 0

Author

N. J. A. Sloane, Aug 18 2006

Keywords

• nonn
• tabl

Examples

			Triangle begins
1
1 1
1 1 1
1 2 2 1
2 3 5 2 1
3 8 11 8 3 1
6 16 30 22 13 3 1
		

References

• J. Brunvoll, S. J. Cyvin and B. N. Cyvin, Isomer enumeration of polygonal systems..., J. Molec. Struct. (Theochem), 364 (1996), 1-13.

Crossrefs

Columns give A002215, A121133-A121136.