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%I #9 Aug 27 2022 13:47:41
%S 0,43,9615,2299822,507491696,118805048562,25315296119626,
%T 5959615271620724
%N a(n) is the first component x of the distance vector (x,y) in an oblique 120-degree coordinate system, 0 <= y <= x, between two nodes of an infinite triangular lattice of one-ohm resistors, such that the resistance R between the two nodes is as close as possible to n ohms, i.e., abs(R - n) is minimized. y is A356204(n).
%e n x y R(x,y) - n
%e 0 0 0 0
%e 1 43 18 5.033*10^(-6)
%e 2 9615 2536 1.848*10^(-10)
%e 3 2299822 1136101 -3.120*10^(-14)
%e 4 507491696 119227930 5.751*10^(-19)
%e 5 118805048562 33636581266 5.618*10^(-23)
%e 6 25315296119626 1774960492720 8.406*10^(-29)
%e 7 5959615271620724 685318499093455 2.526*10^(-32)
%Y Cf. A355585, A355586, A355587, A355588, A355589, A355954.
%Y Cf. A356201, A356202 (similar for square lattice).
%K nonn,hard,more
%O 0,2
%A _Hugo Pfoertner_, Aug 13 2022
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