A289364 Numbers k such that phi(x) = 12*k+2 is solvable, where phi is Euler's totient A000010.

0, 9, 42, 180, 285, 414, 567, 945, 1109, 1419, 2310, 2655, 3024, 4275, 4740, 5229, 5742, 8034, 10005, 10710, 12192, 14595, 15444, 16317, 18135, 19080, 20049, 21042, 22306, 26367, 28665, 29850, 34830, 36135, 38817, 43020, 45942, 56925, 58590, 61992, 65490

Offset

1,2

Comments

The associated values in A002202 are 2, 110, 506, 2162, 3422, ....

Links

Giovanni Resta, Table of n, a(n) for n = 1..10000

J. B. Dence and T. P. Dence, A surprise regarding the equation phi(x)=2*(6*n+1), Coll. Math. J. 26 (4) (1995) 297-301.

Formula

{k: 12*k+2 in A002202}.

Mathematica

phibnd[n_] := n/(Exp[EulerGamma] Log[Log[n]] + 3/Log[Log[n]]); up = 66000; m = 10^4; While[phibnd[m] <= 12 up + 2, m += 10^4]; Union@ Select[ (EulerPhi@ Range @ m - 2)/12, IntegerQ[#] && # <= up &] (* Giovanni Resta, Jul 04 2017 *)

Crossrefs

Cf. A000010, A002202.

Sequence in context: A293101 A084899 A268622 * A074443 A221425 A007227

Adjacent sequences: A289361 A289362 A289363 * A289365 A289366 A289367

Keyword

nonn

Author

R. J. Mathar, Jul 04 2017

Extensions

More terms from Giovanni Resta, Jul 04 2017

Status

approved