A173771 Primes of form (4*10^n+23)/9.
3, 7, 47, 4447, 4444444447, 44444444444444444447, 44444444444444444444444447
Offset: 1
Keywords
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..8
Crossrefs
Cf. A173772
Equals 3 followed by A092480 (primes of the form 40*R_n + 7). - Klaus Brockhaus and R. J. Mathar, Feb 27 2010
Cf. A056682.
Programs
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Magma
[a: n in [0..100] | IsPrime(a) where a is (4*10^n+23)div 9 ]; // Vincenzo Librandi, Jul 26 2012
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Mathematica
Select[Table[(4*10^n+23)/9,{n,0,100}],PrimeQ] (* Vincenzo Librandi, Jul 26 2012 *)
Comments