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A144226
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Prime numbers containing equal number of odd and even digits.
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4
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23, 29, 41, 43, 47, 61, 67, 83, 89, 1009, 1021, 1049, 1061, 1063, 1069, 1087, 1201, 1223, 1229, 1249, 1283, 1289, 1409, 1423, 1427, 1429, 1447, 1481, 1483, 1487, 1489, 1601, 1607, 1609, 1621, 1627, 1663, 1667, 1669, 1801, 1823, 1847, 1861, 1867, 1889
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Can it be proved that this sequence has relative density 0 in the primes? Numbers with equal numbers of even and odd decimal digits have k * n/sqrt(log(n)) members up to n (k varies by upper or lower density). [Charles R Greathouse IV, Nov 12 2010]
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LINKS
| T. D. Noe, Table of n, a(n) for n = 1..10000
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EXAMPLE
| The prime 1889 contains equal number of odd and even digits.
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MATHEMATICA
| fQ[n_] := Block[{id = IntegerDigits[n]}, Length[Select[id, OddQ]] == Length[Select[id, EvenQ]]]; Select[Prime[Range[300]], fQ] [From Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 24 2008]
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CROSSREFS
| Cf. A000040, A144205.
Sequence in context: A101802 A156983 A174196 * A173709 A094383 A166565
Adjacent sequences: A144223 A144224 A144225 * A144227 A144228 A144229
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KEYWORD
| nonn,base
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AUTHOR
| Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Sep 15 2008
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