A332386 Numbers k such that k and k + 1 have the same number of divisors in Eisenstein integers.

3, 7, 32, 50, 68, 174, 184, 200, 212, 219, 247, 291, 328, 343, 368, 376, 435, 472, 495, 543, 579, 608, 644, 679, 712, 716, 723, 788, 795, 849, 860, 871, 874, 904, 932, 939, 1011, 1015, 1058, 1074, 1076, 1159, 1184, 1220, 1227, 1336, 1359, 1384, 1436, 1495, 1515

Offset

1,1

Links

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

Example

3 is a term since 3 and 4 both have 3 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]; SequencePosition[eisNumDiv /@ Range[1520], {x_, x_}][[All, 1]] (* after Harvey P. Dale at A005237 *)

Crossrefs

Cf. A005237, A319442, A332312, A332387, A332388.

Sequence in context: A167917 A249761 A163081 * A096239 A074699 A115088

Adjacent sequences: A332383 A332384 A332385 * A332387 A332388 A332389

Keyword

nonn

Author

Amiram Eldar, Feb 10 2020

Status

approved