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Search: id:A156976
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| A156976 |
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Primes where the last digit is not a prime but all the other digits are primes. |
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1
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| 29, 31, 59, 71, 79, 229, 239, 251, 271, 331, 359, 379, 521, 571, 739, 751, 2221, 2239, 2251, 2339, 2351, 2371, 2521, 2531, 2539, 2551, 2579, 2729, 2731, 3221, 3229, 3251, 3259, 3271, 3329, 3331, 3359, 3371, 3529, 3539, 3559, 3571, 3739, 3779, 5231, 5279
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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It is obvious that the last digit must be a 1 or 9. It is also obvious that the digits 0, 4, 6, or 8 cannot occur anywhere in the numbers.
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LINKS
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Chris Caldwell, The First 1,000 Primes
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EXAMPLE
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751 is a prime in which the last digit is not a prime but the other digits are primes.
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MAPLE
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a := proc (n) local n1, n2, n3: n1 := ithprime(n): n2 := convert(n1, base, 10): n3 := convert(convert(floor((1/10)*n1), base, 10), set): if member(n2[1], {1, 9}) = true and `subset`(n3, {2, 3, 5, 7}) = true then n1 else end if end proc: seq(a(n), n = 1 .. 750); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 15 2009]
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CROSSREFS
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Cf. A000040, A156553
Sequence in context: A132240 A132243 A125523 this_sequence A157681 A077286 A158342
Adjacent sequences: A156973 A156974 A156975 this_sequence A156977 A156978 A156979
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KEYWORD
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base,nonn
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AUTHOR
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Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Feb 19 2009
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 15 2009
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