A064712 - OEIS

%I #29 Jun 02 2023 01:11:43

%S 6,10,12,18,24,28,30,40,42,48,60,76,96,104,108,114,138,146,160,166,

%T 174,176,186,190,196,198,208,230,250,258,262,270,292,296,318,320,334,

%U 336,348,356,358,362,370,372,376,382,400,420,444,454,462,472,488,494,504

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

%C A073497(a(n)) is a prime. - _Zak Seidov_, Apr 11 2011

%H Harry J. Smith, <a href="/A064712/b064712.txt">Table of n, a(n) for n = 1..1000</a>

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

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

%o (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

%o (Magma) [n: n in [6..1000] | IsPrime(n^2-NthPrime(n))]; // _Vincenzo Librandi_, Apr 14 2011

%K easy,nonn

%O 1,1

%A _Robert G. Wilson v_, Oct 13 2001