Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A060515
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A060515 Integers i > 1 for which there is no prime p such that i is a solution mod p of x^2 = 2. +0
2
2, 10, 28, 39, 45, 54, 58, 74, 87, 88, 101, 108, 114, 116, 130, 143, 147, 156, 164, 168, 178, 180, 181, 225, 228, 235, 238, 242, 244, 248, 256, 263, 270, 271, 277, 304, 305, 317, 318, 325, 333, 334, 338, 347, 363, 367, 373, 374, 378, 380, 381, 386, 397, 402 (list; graph; listen)
OFFSET

1,1

COMMENT

Solutions mod p are represented by integers from 0 to p-1. The following equivalences holds for i > 1: There is a prime p such that i is a solution mod p of x^2 = 2 iff i^2-2 has a prime factor > i; i is a solution mod p of x^2 = 2 iff p is a prime factor of i^2-2 and p > i.

FORMULA

Integer i > 1 is a term of this sequence iff i^2-2 has no prime factor > i.

EXAMPLE

a(1) = 2, since there is no prime p such that 2 is a solution mod p of x^2 = 2. a(2) = 10, since there is no prime p such that 10 is a solution mod p of x^2 = 2, and for each integer i from 3 to 9 there is a prime q such that i is a solution mod q of x^2 = 2 (cf. A059772).

CROSSREFS

A038873, A059772.

Sequence in context: A099583 A133479 A057753 this_sequence A109723 A053594 A006331

Adjacent sequences: A060512 A060513 A060514 this_sequence A060516 A060517 A060518

KEYWORD

nonn

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Mar 24 2001

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified July 4 18:25 EDT 2008. Contains 140886 sequences.


AT&T Labs Research