%I #5 Mar 30 2012 16:47:46
%S 1,9,7,81,126,49,729,1701,1323,343,6561,20412,23814,12348,2401,59049,
%T 229635,357210,277830,108045,16807,531441,2480058,4822335,5000940,
%U 2917215,907578,117649,4782969,26040609,60761421,78764805
%N Triangle whose (i,j)-th entry is binomial(i,j)*9^(i-j)*7^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_.