A123354 Triangle read by rows, giving Kekulé numbers for certain benzenoids (see the Cyvin-Gutman book for details).

1, 1, 1, 1, 3, 1, 1, 6, 9, 1, 1, 10, 40, 27, 1, 1, 15, 125, 272, 81, 1, 1, 21, 315, 1625, 1856, 243, 1

Offset

0,5

References

S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p. 210).

Links

Table of n, a(n) for n=0..27.

Example

Triangle begins:
1
1 1
1 3 1
1 6 9 1
1 10 40 27 1
1 15 125 272 81 1
1 21 315 1625 1856 243 1

Crossrefs

Diagonals give A000244, A123357, A123358.

Sequence in context: A371967 A202605 A298636 * A120247 A235113 A235116

Adjacent sequences: A123351 A123352 A123353 * A123355 A123356 A123357

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Oct 14 2006

Status

approved