|
| |
|
|
A070179
|
|
Primes p such that x^2 = 2 has a solution mod p, but x^(2^2) = 2 has no solution mod p.
|
|
11
| |
|
|
17, 41, 97, 137, 193, 241, 313, 401, 409, 433, 449, 457, 521, 569, 641, 673, 761, 769, 809, 857, 929, 953, 977, 1009, 1129, 1297, 1321, 1361, 1409, 1489, 1657, 1697, 1873, 1993, 2017, 2081, 2137, 2153, 2161, 2297, 2377, 2417, 2521, 2609, 2617, 2633, 2713
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
FORMULA
| Primes of the form 8*k + 1 but not x^2 + 64*y^2. - Michael Somos Mar 22 2008
|
|
|
PROG
| (PARI) forprime(p=2, 2720, x=0; while(x<p&&x^2%p!=2%p, x++); if(x<p, y=0; while(y<p&&y^(2^2)%p!=2%p, y++); if(y==p, print1(p, ", "))))
(PARI) {a(n) = local(m, c, x); if( n<1, 0, c = 0; m = 1; while( c<n, m++; if( isprime(m) & m%8 == 1, x = 0; for(y=1, sqrtint( m \ 64 ), if( issquare( m - 64 * y^2, &x), break)); if( !x, c++ ))); m)} /* Michael Somos Mar 22 2008 */
|
|
|
CROSSREFS
| Cf. A038873, A040098, A040100, A059667, A070180 - A070188, A014754.
Sequence in context: A107181 A158014 A139879 * A155072 A145991 A089637
Adjacent sequences: A070176 A070177 A070178 * A070180 A070181 A070182
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 29 2002
|
| |
|
|
