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%I #7 May 26 2020 17:40:28
%S 1,7,4,49,56,16,343,588,336,64,2401,5488,4704,1792,256,16807,48020,
%T 54880,31360,8960,1024,117649,403368,576240,439040,188160,43008,4096,
%U 823543,3294172,5647152,5378240,3073280,1053696,200704,16384
%N Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*4^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.
%t Table[Binomial[n,k]7^(n-k) 4^k,{n,0,10},{k,0,n}]//Flatten (* _Harvey P. Dale_, May 26 2020 *)
%K nonn,tabl,easy
%O 0,2
%A _N. J. A. Sloane_.