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A038215 Triangle whose (i,j)-th entry is binomial(i,j)*2^(i-j)*9^j. 0

%I

%S 1,2,9,4,36,81,8,108,486,729,16,288,1944,5832,6561,32,720,6480,29160,

%T 65610,59049,64,1728,19440,116640,393660,708588,531441,128,4032,54432,

%U 408240,1837080,4960116,7440174,4782969,256,9216,145152

%N Triangle whose (i,j)-th entry is binomial(i,j)*2^(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.

%t Table[Binomial[x,y]2^(x-y) 9^y,{x,0,10},{y,0,x}]//Flatten (* _Harvey P. Dale_, Jun 17 2017 *)

%K nonn,tabl,easy

%O 0,2

%A _N. J. A. Sloane_.

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)