A267819 Primes whose base-5 representation is a square when read in base 10.

89, 139, 4801, 6829, 9601, 48661, 305551, 539849, 867001, 3503449, 3527071, 6063839, 13912039, 15933439, 18100351, 18319321, 20366399, 22849121, 26239321, 46724801, 63565049, 78057911, 95802799, 100294871, 102369439, 107474911, 139769449, 141118079, 144829879, 159468079, 161483801

Offset: 1

Author

Christopher Cormier, Jan 20 2016

Keywords

• nonn
• base

Comments

Primes in the sequence A267765.

Examples

			89 in base 5 is 324, and 324 = 18^2 in base 10.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..10000

Crossrefs

In other bases: A267817 - A267821, A241246, A267490.

Programs

Mathematica

Select[Prime@ Range[10^6], IntegerQ@ Sqrt@ FromDigits@ IntegerDigits[#, 5] &] (* Michael De Vlieger, Jan 24 2016 *)

Python

from sympy import isprime
A267819_list = [int(d,5) for d in (str(i**2) for i in range(1,10**6)) if max(d) < '5' and isprime(int(d,5))] # Chai Wah Wu, Feb 22 2016