A120653 - OEIS

%I #3 Mar 30 2012 16:50:29

%S 1,1,1,1,1,1,2,3,3,1,6,10,11,3,1,20,46,48,21,5,1,72,192,228,116,37,5,

%T 1,272,840,1080,692,254,55,7,1,1056,3584,5112,3776,1690,446,79,7,1,

%U 4160,15392,23920,20216,10476,3474,748,105,9,1,16512,65536,11084,104448

%N Triangle read by rows: numbers of isomers of unbranched a-4-catapolyheptagons.

%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 2 3 3 1

%e 6 10 11 3 1

%e 20 46 48 21 5 1

%e 72 192 228 116 37 5 1

%Y Columns give A063376, A121138-A121141.

%K nonn,tabl

%O 0,7

%A _N. J. A. Sloane_, Aug 18 2006