A172469 - OEIS

A172469

Primes congruent to +/-1 or +/-7 modulo 25.

7, 43, 101, 107, 149, 151, 157, 193, 199, 251, 257, 293, 307, 349, 401, 443, 449, 457, 499, 557, 593, 599, 601, 607, 643, 701, 743, 751, 757, 857, 907, 1049, 1051, 1093, 1151, 1193, 1201, 1249, 1301, 1307, 1399, 1451, 1493, 1499, 1543, 1549, 1601, 1607

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OFFSET

1,1

COMMENTS

Equivalently, primes p such that the smallest extension of F_p containing the 5th roots of unity also contains the 25th roots of unity.

In this respect, the sequence is the n=5 instance of a family of sequences. For n=3, see A129805, and for n=2, see A002144.

Equivalently, the primes p for which, if p^t = 1 mod 5, then p^t = 1 mod 25.

LINKS

Table of n, a(n) for n=1..48.

FORMULA

A141927 U A141932 U A141946 U A141941. [From R. J. Mathar, Feb 05 2010]

CROSSREFS