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A267819 Primes whose base-5 representation is a square when read in base 10. 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Primes in the sequence A267765.
LINKS
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
KEYWORD
nonn,base
AUTHOR
Christopher Cormier, Jan 20 2016
STATUS
approved

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Last modified April 18 04:56 EDT 2024. Contains 371767 sequences. (Running on oeis4.)