%I #5 Mar 30 2012 16:47:46
%S 1,3,9,9,54,81,27,243,729,729,81,972,4374,8748,6561,243,3645,21870,
%T 65610,98415,59049,729,13122,98415,393660,885735,1062882,531441,2187,
%U 45927,413343,2066715,6200145,11160261,11160261,4782969,6561
%N Triangle whose (i,j)-th entry is binomial(i,j)*3^(i-j)*9^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_.