A064712 Numbers k such that k^2 - prime(k) is a prime.

6, 10, 12, 18, 24, 28, 30, 40, 42, 48, 60, 76, 96, 104, 108, 114, 138, 146, 160, 166, 174, 176, 186, 190, 196, 198, 208, 230, 250, 258, 262, 270, 292, 296, 318, 320, 334, 336, 348, 356, 358, 362, 370, 372, 376, 382, 400, 420, 444, 454, 462, 472, 488, 494, 504

Offset

1,1

Comments

A073497(a(n)) is a prime. - Zak Seidov, Apr 11 2011

Links

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

Example

6 is in the sequence because 6^2 - prime(6) = 36 - 13 = 23 is a prime.

Mathematica

Select[ Range[ 6, 1000, 2 ], PrimeQ[ #^2 - Prime[ # ] ] & ]

Prog

(PARI) n=0; forstep (m=6, 10^9, 2, if (isprime(m^2 - prime(m)), write("b064712.txt", n++, " ", m); if (n==1000, break)) ) \\ Harry J. Smith, Sep 23 2009
(Magma) [n: n in [6..1000] | IsPrime(n^2-NthPrime(n))]; // Vincenzo Librandi, Apr 14 2011

Crossrefs

Sequence in context: A315131 A046288 A076763 * A348629 A284667 A315132

Adjacent sequences: A064709 A064710 A064711 * A064713 A064714 A064715

Keyword

easy,nonn

Author

Robert G. Wilson v, Oct 13 2001

Status

approved