A120649 Triangle read by rows: numbers of isomers of unbranched a-4-catapolyoctagons.

1, 1, 1, 1, 1, 1, 3, 4, 4, 1, 9, 16, 16, 4, 1, 39, 85, 84, 32, 7, 1, 169, 439, 465, 210, 57, 7, 1, 819, 2358, 2714, 1495, 469, 86, 10, 1, 3969, 12502, 15732, 10014, 3750, 834, 124, 10, 1, 19719, 66471, 90934, 65746, 28604, 7864, 1410, 166, 13, 1

Offset

0,7

References

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

Links

Table of n, a(n) for n=0..54.

Example

Triangle begins:
1
1 1
1 1 1
3 4 4 1
9 16 16 4 1
39 85 84 32 7 1
169 439 465 210 57 7 1

Crossrefs

Columns give A121101, A121145, A121146.

Sequence in context: A054733 A204255 A283753 * A001009 A120650 A103121

Adjacent sequences: A120646 A120647 A120648 * A120650 A120651 A120652

Keyword

nonn,tabl

Author

N. J. A. Sloane, Aug 18 2006

Status

approved