A121952 Number of isomeric aza-benzenoids with four nitrogen atoms and n hexagons.

3, 22, 194, 1620, 12982, 98765, 720519, 5073805, 34707100, 231739037

Offset: 1

Author

Parthasarathy Nambi, Sep 04 2006

Keywords

• nonn

Examples

			If n=5 then the number of isomeric aza-benzenoids with four nitrogen atoms is 12982. Here n is the number of hexagons.
		

References

• N. Trinajstich, Z. Jericevic, J. V. Knop, W. R. Muller and K. Szymanski, "Computer generation of isomeric structures", Pure and Appl. Chem., vol. 55 (1983) pp. 379-390.