A240839 Both n and prime(n) are primes congruent to 3 (mod 10).

23, 103, 293, 503, 823, 883, 953, 983, 1033, 1163, 1213, 1223, 1433, 1453, 1493, 1523, 1723, 1733, 1933, 1993, 2113, 2203, 2803, 2833, 2903, 3023, 3203, 3343, 3433, 3733, 3823, 3833, 4003, 4243, 4373, 4483, 4513, 4733, 4813, 4903, 4943, 4993, 5333, 5503, 5743, 6143, 6343, 6833, 7013

Offset: 1

Author

Zak Seidov, Apr 13 2014

Keywords

• nonn

Comments

Intersection of A030431 and A049508.

Examples

			prime(23, 103, 293, 503, 823, 883, 953, 983, 1033, 1163)  =  (83, 563, 1913, 3593, 6323, 6863, 7523, 7753, 8233, 9403).
		

Links

• Zak Seidov, Table of n, a(n) for n = 1..469

Crossrefs

Cf. A030431, A049508.

Programs

Mathematica

Intersection[A030431 = Select[Range[3, 1000003, 10], PrimeQ], PrimePi[A030431]] (* gives 469 terms for prime(n) up to 10^6 *)
Select[Prime[Range[50000]],Mod[#,10]==Mod[Prime[#],10]==3&] (* gives 3126 terms from the first 50000 primes *)(* Harvey P. Dale, Nov 29 2014 *)

PARI

s=[]; forprime(n=2, 8000, if(n%10==3 && prime(n)%10==3, s=concat(s, n))); s \\ Colin Barker, Apr 16 2014