%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