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Search: id:A068492
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| A068492 |
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Primes which remain prime after each digit is replaced by its square. |
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+0
1
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| 11, 13, 17, 19, 71, 73, 89, 101, 103, 107, 131, 137, 149, 167, 173, 191, 197, 199, 223, 229, 233, 283, 307, 311, 313, 331, 337, 359, 383, 401, 433, 439, 461, 463, 491, 523, 569, 593, 631, 641, 647, 659, 709, 733, 743, 773, 809, 823, 859
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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When each digit of the prime 89 is replaced by its square, 6481, a prime, results. Hence 89 is a term of the sequence.
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MATHEMATICA
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f[n_] := Block[{a = IntegerDigits[n], b = "", k = 1, l}, l = Length[a]; While[k < l + 1, b = StringJoin[b, ToString[a[[k]]^2]]; k++ ]; ToExpression[b]]; Do[ If[ PrimeQ[ f[ Prime[n]]], Print[ Prime[n]]], {n, 1, 150} ]
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CROSSREFS
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Sequence in context: A157175 A132244 A087201 this_sequence A045707 A032591 A088265
Adjacent sequences: A068489 A068490 A068491 this_sequence A068493 A068494 A068495
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KEYWORD
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base,nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Mar 11 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com) Mar 19 2002
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