A102624 Numbers k such that the number k23 is prime.
0, 2, 5, 8, 11, 12, 14, 15, 17, 18, 24, 30, 33, 36, 38, 39, 44, 45, 47, 50, 53, 56, 59, 63, 68, 75, 77, 78, 81, 84, 86, 89, 93, 96, 99, 102, 107, 114, 119, 123, 128, 129, 135, 137, 143, 144, 147, 149, 158, 159, 162, 168, 171, 176, 179, 182, 185, 194, 200, 201, 203, 210
Offset: 1
Examples
If k=2, then k23 = 223 (prime). If k=45, then k23 = 4523 (prime). If k=99, then k23 = 9923 (prime).
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Magma
[ n: n in [1..700] | IsPrime(Seqint([3,2] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 04 2011; misses the zero
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Mathematica
Select[Range[0,300],PrimeQ[100#+23]&] (* Harvey P. Dale, Apr 08 2019 *)
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PARI
is(n)=isprime(100*n+23) \\ Charles R Greathouse IV, Jun 06 2017
Extensions
More terms from Robert G. Wilson v, Feb 04 2005