A332530 Numbers k such that k and k + 1 has the same value of A319445, the equivalent of the Euler totient function in the ring of Eisenstein integers.

34, 51, 152, 679, 1065, 1845, 6525, 12122, 12970, 15656, 38607, 48398, 175473, 272935, 401505, 953342, 1035895, 1210054, 1222988, 1406665, 1589245, 1607095, 2108186, 2116975, 2272425, 2500615, 2751160, 3399591, 4542225, 5298559, 5412986, 6813585, 6898736, 7115553

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..152

Example

34 is a term since A319445(34) = A319445(35) = 864.

Mathematica

f[p_, e_] := If[p == 3, 2*3^(2*e - 1), Switch[Mod[p, 3], 1, (p - 1)^2*p^(2*e - 2), 2, (p^2 - 1)*p^(2*e - 2)]]; eisPhi[1] = 1; eisPhi[n_] := Times @@ f @@@ FactorInteger[n]; seq = {}; e1 = eisPhi[1]; Do[e2 = eisPhi[n]; If[e1 == e2, AppendTo[seq, n - 1]]; e1 = e2, {n, 2, 10^6}]; seq

Crossrefs

Cf. A001274, A287055, A293184, A319445, A326403, A332316.

Sequence in context: A260468 A051991 A214473 * A092888 A217768 A217704

Adjacent sequences: A332527 A332528 A332529 * A332531 A332532 A332533

Keyword

nonn

Author

Amiram Eldar, Feb 15 2020

Status

approved