%I #5 Mar 30 2012 16:47:46
%S 1,9,3,81,54,9,729,729,243,27,6561,8748,4374,972,81,59049,98415,65610,
%T 21870,3645,243,531441,1062882,885735,393660,98415,13122,729,4782969,
%U 11160261,11160261,6200145,2066715,413343,45927,2187
%N Triangle whose (i,j)-th entry is binomial(i,j)*9^(i-j)*3^j.
%D B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.
%K nonn,tabl,easy
%O 0,2
%A _N. J. A. Sloane_.