A064937 - OEIS

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A064937

Nonprimes k such that gcd(k, prime(k)^2 - 1) is 1.

1, 25, 49, 55, 77, 119, 133, 143, 155, 161, 169, 185, 187, 203, 209, 217, 221, 235, 247, 275, 287, 289, 295, 301, 325, 329, 361, 365, 371, 377, 391, 403, 407, 415, 425, 427, 437, 451, 455, 469, 473, 485, 493, 497, 505, 511, 517, 527, 529, 539, 553, 559, 583

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[ Range[600], !PrimeQ[ # ] && GCD[ #, Prime[ # ]^2 - 1] == 1 & ]

PROG

(PARI) { n=0; for (m=1, 10^9, if (isprime(m), next); if (gcd(m, prime(m)^2 - 1) == 1, write("b064937.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Sep 30 2009

CROSSREFS

Cf. A064830.

Sequence in context: A273510 A198591 A069063 * A245272 A091300 A112771

Adjacent sequences: A064934 A064935 A064936 * A064938 A064939 A064940

KEYWORD

easy,nonn

AUTHOR

Robert G. Wilson v, Oct 26 2001

STATUS

approved