A356203 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).

0, 43, 9615, 2299822, 507491696, 118805048562, 25315296119626, 5959615271620724

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Example

  n                   x                  y    R(x,y) - n
  0                   0                  0    0
  1                  43                 18    5.033*10^(-6)
  2                9615               2536    1.848*10^(-10)
  3             2299822            1136101   -3.120*10^(-14)
  4           507491696          119227930    5.751*10^(-19)
  5        118805048562        33636581266    5.618*10^(-23)
  6      25315296119626      1774960492720    8.406*10^(-29)
  7    5959615271620724    685318499093455    2.526*10^(-32)

Crossrefs

Cf. A355585, A355586, A355587, A355588, A355589, A355954.

Cf. A356201, A356202 (similar for square lattice).

Sequence in context: A147522 A183489 A361892 * A184144 A262856 A302484

Adjacent sequences: A356200 A356201 A356202 * A356204 A356205 A356206

Keyword

nonn,hard,more

Author

Hugo Pfoertner, Aug 13 2022

Status

approved