A235110 Primes whose base-10 representation also represents a prime in base 13.
2, 3, 5, 7, 23, 41, 47, 61, 83, 89, 157, 173, 179, 197, 223, 229, 263, 281, 311, 313, 331, 373, 379, 397, 401, 463, 467, 487, 571, 599, 607, 643, 661, 739, 751, 773, 797, 809, 823, 863, 883, 919, 937, 971, 977
Offset: 1
Examples
The decimal representation of prime 23, considered as a number written in base 13, stands for 2*13+3 = 29, which is also prime, therefore 23 is in the sequence.
Links
- Zak Seidov, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Prime[Range[5000]],PrimeQ[FromDigits[IntegerDigits[#],13]]&] (* Zak Seidov, Aug 31 2015 *)
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PARI
is_A235110(p, b=13)={my(d=digits(p)); isprime(vector(#d, i, b^(#d-i))*d~)&&isprime(p)}
Comments