A332388 Numbers k such that k, k + 1, k + 2 and k + 3 have the same number of divisors in Eisenstein integers.

34193750, 76788050, 78267398, 113004199, 135383873, 148843670, 170293249, 199259222, 311313398, 318128599, 364828550, 368222599, 381026822, 384839047, 420686749, 428129222, 430154150, 432466824, 450050450, 462825847, 492828521, 510703975, 517126773, 518268772

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Example

34193750 is a term since 34193750, 34193751, 34193752 and 34193750 each have 24 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]; m = 4; s = eisNumDiv /@ Range[m]; seq = {}; n = m + 1; While[Length[seq] < 10, If[Length @ Union[s] == 1, AppendTo[seq, n - m + 1]]; n++; s = Join[Rest[s], {eisNumDiv[n]}]]; seq

Crossrefs

Cf. A006601, A319442, A332314, A332386, A332387.

Sequence in context: A345122 A363295 A172687 * A271769 A290038 A289957

Adjacent sequences: A332385 A332386 A332387 * A332389 A332390 A332391

Keyword

nonn

Author

Amiram Eldar, Feb 10 2020

Status

approved