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A082646
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Primes whose decimal expansions contain equal numbers of each of their digits.
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1
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2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 103, 107, 109, 127, 137, 139, 149, 157, 163, 167, 173, 179, 193, 197, 239, 241, 251, 257, 263, 269, 271, 281, 283, 293, 307, 317, 347, 349, 359, 367, 379, 389, 397, 401
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OFFSET
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1,1
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COMMENTS
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All repunit primes (A004022) are terms. There are no terms of prime p digit- length for p >= 11 unless p is a term of A004023 - in which case there is exactly one such term here, the repunit prime of length p. The smallest term whose digits are neither all the same nor all different is 100313. No term of digit-length 10 can have digits all different because such a term would be divisible by 3 (as 45, the sum of its digits, would be divisible by 3).
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LINKS
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EXAMPLE
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The prime 101 is not a term because it contains two 1's but only one 0. The
prime 127 is a term because it has one 1, one 2 and one 7.
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MATHEMATICA
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t={}; Do[p=Prime[n]; If[Length[DeleteDuplicates[Transpose[Tally[IntegerDigits[p]]][[2]]]]==1, AppendTo[t, p]], {n, 79}]; t (* Jayanta Basu, May 10 2013 *)
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PROG
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(Python)
from sympy import prime
for i in range(1, 10**5):
p = str(prime(i))
h = [p.count(d) for d in '0123456789' if d in p]
if min(h) == max(h):
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CROSSREFS
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Cf. A004022 (repunit primes), A004023 (digit lengths of repunit primes).
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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