%I A123352
%S A123352 1,1,1,1,2,1,1,3,5,1,1,4,14,14,1,1,5,30,84,42,1,1,6,55,330,594,132,1,1,
%T A123352 7,91,1001,4719,4719,429,1,1,8,140,2548,26026,81796,40898,1430,1,1,9,
%U A123352 204,5712,111384,884884,1643356,379236,4862,1
%N A123352 Triangle read by rows, giving numbers of benzenoids (see the Cyvin-Gutman 
               book for details).
%C A123352 There is another version in A078920 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), 
               Apr 12 2007
%D A123352 S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, 
               Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see 
               p. 183).
%F A123352 Triangle T(n,k)=(-1)^C(k+1,2)*Product{1<=i<=j<=k, (-2(n+1)+i+j)/(i+j)}. 
               [From Paul Barry (pbarry(AT)wit.ie), Jan 22 2009]
%e A123352 Triangle begins:
%e A123352 1
%e A123352 1 1
%e A123352 1 2 1
%e A123352 1 3 5 1
%e A123352 1 4 14 14 1
%e A123352 1 5 30 84 42 1
%e A123352 1 6 55 330 594 132 1
%e A123352 1 7 91 1001 4719 4719 429 1
%Y A123352 Diagonals give A000108, A005700, A006149, A006150, A006151, etc.
%Y A123352 Cf. A000012, A000027, A000330, A006858, A091962.
%Y A123352 Sequence in context: A111672 A128198 A123349 this_sequence A114163 A090234 
               A007754
%Y A123352 Adjacent sequences: A123349 A123350 A123351 this_sequence A123353 A123354 
               A123355
%K A123352 nonn,tabl
%O A123352 0,5
%A A123352 N. J. A. Sloane (njas(AT)research.att.com), Oct 14 2006
%E A123352 More terms from Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Apr 12 2007