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A046395
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Palindromes that are the product of 5 distinct primes.
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4
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6006, 8778, 20202, 28182, 41514, 43134, 50505, 68586, 87978, 111111, 141141, 168861, 202202, 204402, 209902, 246642, 249942, 262262, 266662, 303303, 323323, 393393, 399993, 438834, 454454, 505505, 507705, 515515, 516615, 519915, 534435, 535535, 543345
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OFFSET
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1,1
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COMMENTS
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No exponent of the distinct prime factors can be greater than one, i.e., no prime powers are permitted. - Harvey P. Dale, Apr 09 2021 at the suggestion of Sean A. Irvine
See A373465 for the similar sequence where only distinct prime divisors are counted, but may occur to higher powers. - M. F. Hasler, Jun 06 2024
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LINKS
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FORMULA
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EXAMPLE
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505505 = 5 * 7 * 11 * 13 * 101.
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MATHEMATICA
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Select[Range[550000], PalindromeQ[#]&&PrimeNu[#]==PrimeOmega[#]==5&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 09 2021 *)
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CROSSREFS
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Cf. A046331 (palindromes with 5 prime factors counted with multiplicity), A373465 (counting only distinct prime divisors).
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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Corrected at the suggestion of Sean A. Irvine by Harvey P. Dale, Apr 09 2021
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STATUS
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approved
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