A175762 Primes with an arithmetic mean of digits which is also prime.

2, 3, 5, 7, 13, 19, 31, 37, 59, 73, 1061, 1151, 1223, 1289, 1487, 1511, 1559, 1601, 1667, 1847, 1973, 1999, 2099, 2141, 2213, 2297, 2411, 2459, 2477, 2549, 2657, 2693, 2729, 2819, 2837, 2909, 2927, 2963, 3023, 3041, 3089, 3203, 3221, 3359, 3449, 3467, 3539, 3557

Offset: 1

Author

Juri-Stepan Gerasimov, Aug 29 2010

Keywords

• nonn
• base
• easy

Examples

			a(10)=73 because (7+3)/2=5=prime. a(12)=1151 because (1+1+5+1)/4=2=prime.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A007605, A061383.

Programs

Mathematica

Select[Prime[Range[500]],PrimeQ[Mean[IntegerDigits[#]]]&] (* Harvey P. Dale, Jan 16 2013 *)

Formula

{A000040(i): A007605(i)/A097944(i) in A000040}.

Extensions

Corrected (59 inserted, 1061 inserted etc.) by R. J. Mathar, Sep 24 2010