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Triangle whose (i,j)-th entry is binomial(i,j)*10^(i-j)*2^j.
0

%I #20 May 23 2024 04:25:43

%S 1,10,2,100,40,4,1000,600,120,8,10000,8000,2400,320,16,100000,100000,

%T 40000,8000,800,32,1000000,1200000,600000,160000,24000,1920,64,

%U 10000000,14000000,8400000,2800000,560000,67200,4480,128,100000000

%N Triangle whose (i,j)-th entry is binomial(i,j)*10^(i-j)*2^j.

%H B. N. Cyvin, J. Brunvoll, and S. J. Cyvin, <a href="http://match.pmf.kg.ac.rs/electronic_versions/Match34/match34_109-121.pdf">Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons</a>, Match, No. 34 (Oct 1996), 109-121.

%F G.f.: 1/(1 - 10*x - 2*x*y). - _Stefano Spezia_, Apr 28 2024

%e From _Stefano Spezia_, Apr 28 2024: (Start)

%e Triangle begins:

%e 1;

%e 10, 2;

%e 100, 40, 4;

%e 1000, 600, 120, 8;

%e 10000, 8000, 2400, 320, 16;

%e 100000, 100000, 40000, 8000, 800, 32;

%e ...

%e (End)

%t Table[Binomial[i,j]*10^(i-j)*2^j,{i,0,7},{j,0,i}]//Flatten (* _Stefano Spezia_, Apr 28 2024 *)

%Y Cf. A000079 (right diagonal), A001021 (row sums), A011557 (1st column).

%K nonn,tabl,easy

%O 0,2

%A _N. J. A. Sloane_