A064269 Numbers k such that prime(k) - k is prime.
3, 4, 6, 8, 10, 14, 16, 18, 28, 30, 42, 44, 50, 54, 66, 68, 76, 84, 90, 94, 110, 144, 148, 154, 168, 174, 178, 192, 196, 214, 220, 242, 264, 266, 268, 278, 280, 282, 294, 304, 308, 336, 346, 348, 354, 358, 360, 370, 376, 380, 382, 384, 390, 400, 402, 408, 414
Offset: 1
Examples
n=54: prime(54) - 54 = 197, a prime.
Links
- Harry J. Smith, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Select[ Range[ 415 ], PrimeQ[ Prime[ # ] - # ] & ]
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PARI
j=[]; for(n=1,500, if(isprime(prime(n)-n), j=concat(j,n))); j
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PARI
{ n=0; for (m=1, 10^9, if (isprime(prime(m) - m), write("b064269.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 10 2009