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

1,1

Comments

Primes in the sequence A267765.

Links

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

Example

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

Mathematica

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

Prog

(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

Crossrefs

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

Sequence in context: A109560 A260557 A141938 * A031416 A340307 A353249

Adjacent sequences: A267816 A267817 A267818 * A267820 A267821 A267822

Keyword

nonn,base

Author

Christopher Cormier, Jan 20 2016

Status

approved