A362182 Unitary noncototient numbers: numbers k such that A323410(x) = k has no solution.

2, 3, 5, 330, 1206, 1210, 1656, 1718, 1806, 1866, 1926, 2376, 2982, 3162, 3186, 3342, 4012, 4062, 4194, 4326, 4502, 4662, 4810, 5322, 5466, 6172, 6402, 6462, 6534, 6546, 6672, 6756, 7266, 7430, 7866, 8030, 8140, 8286, 8386, 8562, 8586, 8860, 9114, 9370, 9516, 9906

Offset

1,1

Comments

Numbers k such that A362181(k) = 0.

Are 3 and 5 the only odd terms? There are no other odd terms below 10^5.

Links

Amiram Eldar, Table of n, a(n) for n = 1..534 (terms below 10^5)

Mathematica

ucototient[n_] := n - Times @@ (Power @@@ FactorInteger[n] - 1); ucototient[1] = 0; With[{max = 2000}, Complement[Range[max], Table[ucototient[n], {n, 1, max^2}]]]

Crossrefs

Cf. A323410, A362181.

The unitary version of A005278.

Similar sequences: A007617, A347771.

Sequence in context: A042579 A033090 A303371 * A046474 A056146 A115835

Adjacent sequences: A362179 A362180 A362181 * A362183 A362184 A362185

Keyword

nonn

Author

Amiram Eldar, Apr 10 2023

Status

approved