A123353 - OEIS

%I #6 Feb 27 2015 22:28:02

%S 1,1,1,1,2,1,1,3,6,1,1,4,20,19,1,1,5,50,155,62,1,1,6,105,805,1315,207,

%T 1

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

%D S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p. 188).

%e Triangle begins:

%e 1

%e 1 1

%e 1 2 1

%e 1 3 6 1

%e 1 4 20 19 1

%e 1 5 50 155 62 1

%e 1 6 105 805 1315 207 1

%Y Diagonals give A026012, A123355, A123356.

%K nonn,tabl,more

%O 0,5

%A _N. J. A. Sloane_, Oct 14 2006