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T(n,m) is the denominator of the resistance between two diametrically opposite nodes of a rectangular electric network of n*m quadratic meshes in which all edges are replaced by one-ohm resistors, where T(n,m) is a triangle read by rows.
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%I #4 Sep 16 2022 13:22:52

%S 1,5,2,8,69,7,19,209,1023,22,15,440,16744,1205,495,71,2639,128617,

%T 4282081,1169441,2494,112,11067,21728,59292739,3498175408,

%U 287916805961,360161,265,4142,5317209,579080689,43600867640,9153575734849,273893674761,153254

%N T(n,m) is the denominator of the resistance between two diametrically opposite nodes of a rectangular electric network of n*m quadratic meshes in which all edges are replaced by one-ohm resistors, where T(n,m) is a triangle read by rows.

%e The triangle begins:

%e 1;

%e 7/5, 3/2;

%e 15/8, 121/69, 13/7;

%e 45/19, 430/209, 2089/1023, 47/22;

%e 43/15, 1047/440, 37873/16744, 2749/1205, 1171/495

%Y A357113 are the corresponding numerators.

%K nonn,frac,tabl

%O 1,2

%A _Hugo Pfoertner_, Sep 15 2022