A084167 Numbers k in A002313 such that the count of primitive roots of k (A084168) are also in sequence A002313, where A002313 is the list of primes p having a unique representation as the sum of two squares, p = x^2 + y^2.

1, 5, 17, 109, 157, 317, 389, 449, 709, 1201, 1237, 1249, 1429, 1621, 1801, 2341, 3001

Offset

1,2

Links

Table of n, a(n) for n=1..17.

Example

449 = 20^2 + 7^2 has 192 primitive roots, of which 41 are prime, of which 20 are in A002313.

Crossrefs

Cf. A002313, A084168.

Sequence in context: A240803 A098028 A100301 * A267143 A331636 A234797

Adjacent sequences: A084164 A084165 A084166 * A084168 A084169 A084170

Keyword

nonn,fini,full,easy

Author

Sven Simon, May 17 2003

Extensions

Offset changed to 1 by Jinyuan Wang, Mar 09 2020

Name edited by Michel Marcus, Mar 09 2020

Status

approved