A063742 Cototients: numbers k such that x - phi(x) = k has at least one solution.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78

Offset

1,3

Comments

Numbers in range of A051853, the cototients. Complement of non-cototients, A005278 with respect to natural numbers A000027.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

First missing numbers are: 10,26,34,50,52,... These missing values are collected in A005278.

Mathematica

Union[Table[w-EulerPhi[w], {w, 1, A}] taken for sufficiently large A.

Crossrefs

Cf. A000010, A005278, A051953, A083533, A083534, A083536.

Analogous to A002202.

Sequence in context: A226134 A057717 A183222 * A014089 A065039 A171397

Adjacent sequences: A063739 A063740 A063741 * A063743 A063744 A063745

Keyword

nonn

Author

Labos Elemer, Aug 13 2001, corrected May 20 2003

Extensions

Edited by N. J. A. Sloane, Nov 17 2008 at the suggestion of R. J. Mathar

Status

approved