A332530 - OEIS

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.

%I #28 Mar 20 2022 16:06:40

%S 34,51,152,679,1065,1845,6525,12122,12970,15656,38607,48398,175473,

%T 272935,401505,953342,1035895,1210054,1222988,1406665,1589245,1607095,

%U 2108186,2116975,2272425,2500615,2751160,3399591,4542225,5298559,5412986,6813585,6898736,7115553

%N 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.

%H Amiram Eldar, <a href="/A332530/b332530.txt">Table of n, a(n) for n = 1..152</a>

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

%t 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

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

%K nonn

%O 1,1

%A _Amiram Eldar_, Feb 15 2020