A120650 Triangle read by rows: numbers of isomers of unbranched a-4-catapolynonagons.

1, 1, 1, 1, 1, 1, 3, 4, 4, 1, 12, 21, 19, 4, 1, 63, 138, 123, 40, 7, 1, 342, 864, 834, 330, 73, 7, 1, 1998, 5526, 5796, 2814, 747, 112, 10, 1, 11772, 34992, 40014, 22464, 7218, 1359, 163, 10, 1, 70308, 221724, 274590, 174798, 65583, 15372, 2307, 220, 13, 1, 420552, 1399680, 1867320, 1321920, 567540, 157284, 29100, 3540, 289, 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..65.

Example

Triangle begins
1
1 1
1 1 1
3 4 4 1
12 21 19 4 1
63 138 123 40 7 1
342 864 834 330 73 7 1

Crossrefs

Columns give A121123-A121127.

Sequence in context: A377968 A120649 A001009 * A103121 A291086 A358449

Adjacent sequences: A120647 A120648 A120649 * A120651 A120652 A120653

Keyword

nonn,tabl

Author

N. J. A. Sloane, Aug 18 2006

Status

approved