A332387 Numbers k such that k, k + 1 and k + 2 have the same number of divisors in Eisenstein integers.

13448, 27848, 75774, 135400, 243338, 276123, 396950, 452823, 497575, 524823, 565674, 587575, 632224, 639848, 719223, 769316, 861123, 935799, 1060904, 1073875, 1153023, 1204312, 1308856, 1366624, 1413498, 1490599, 1555975, 1565223, 1601798, 1767424, 1902774, 1923295

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

13448 is a term since 13448, 13449 and 13450 each have 12 divisors in Eisenstein integers.

Mathematica

f[p_, e_] := Switch[Mod[p, 3], 0, 2*e + 1, 1, (e + 1)^2, 2, e + 1]; eisNumDiv[1] = 1; eisNumDiv[n_] := Times @@ f @@@ FactorInteger[n]; Flatten[Position[Partition[ eisNumDiv /@ Range[10^6], 3, 1], {x_, x_, x_}]] (* after Harvey P. Dale at A005238 *)

Crossrefs

Cf. A005238, A319442, A332313, A332386, A332388.

Sequence in context: A157506 A238176 A035917 * A183676 A204394 A250818

Adjacent sequences: A332384 A332385 A332386 * A332388 A332389 A332390

Keyword

nonn

Author

Amiram Eldar, Feb 10 2020

Status

approved