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A267821 Primes whose base-9 representation is a square in base 10. 4
23, 73, 509, 643, 751, 1093, 1153, 1481, 1783, 2029, 6067, 8011, 8933, 9613, 16061, 24763, 30803, 44203, 64633, 74521, 82723, 88003, 94033, 103171, 106619, 118669, 126541, 133321, 154571, 158293, 163561, 165883, 179821, 197339, 202393, 207643, 225523, 234733, 264083, 268003, 284593, 288661, 324931 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Primes in the sequence A267769.
LINKS
EXAMPLE
73 in base 9 is 81, and 81 = 9^2 in base 10.
MATHEMATICA
Select[Prime@ Range@ 28000, IntegerQ@ Sqrt@ FromDigits@ IntegerDigits[#, 9] &] (* Michael De Vlieger, Jan 24 2016 *)
PROG
(Python)
from sympy import isprime
A267821_list = [int(d, 9) for d in (str(i**2) for i in range(1, 10**6)) if max(d) < '9' and isprime(int(d, 9))] # Chai Wah Wu, Feb 22 2016
CROSSREFS
In other bases: A267817 - A267821, A241246, A267490.
Sequence in context: A044161 A044542 A141945 * A237987 A157270 A102109
KEYWORD
nonn,base
AUTHOR
Christopher Cormier, Jan 20 2016
STATUS
approved

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Last modified April 12 16:59 EDT 2024. Contains 371635 sequences. (Running on oeis4.)