%I #3 Mar 30 2012 16:50:29
%S 1,1,1,1,1,1,3,4,4,1,12,21,19,4,1,63,138,123,40,7,1,342,864,834,330,
%T 73,7,1,1998,5526,5796,2814,747,112,10,1,11772,34992,40014,22464,7218,
%U 1359,163,10,1,70308,221724,274590,174798,65583,15372,2307,220,13,1,420552,1399680,1867320,1321920,567540,157284,29100,3540,289,13,1
%N Triangle read by rows: numbers of isomers of unbranched a-4-catapolynonagons.
%D J. Brunvoll, S. J. Cyvin and B. N. Cyvin, Isomer enumeration of polygonal systems..., J. Molec. Struct. (Theochem), 364 (1996), 1-13.
%e Triangle begins
%e 1
%e 1 1
%e 1 1 1
%e 3 4 4 1
%e 12 21 19 4 1
%e 63 138 123 40 7 1
%e 342 864 834 330 73 7 1
%Y Columns give A121123-A121127.
%K nonn,tabl
%O 0,7
%A _N. J. A. Sloane_, Aug 18 2006