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A256621
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Primes p such that the decimal expansion of p remains prime under three iterations of base-10 to base-2 conversion.
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5
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3893257, 9023533, 11005327, 11659009, 18747809, 21855233, 25183007, 34074379, 54298687, 58562951, 60496981, 89891273, 94277683, 96602887, 102276859, 115555927, 117578429, 122191543, 125115709, 132837283, 138169991, 139442753, 168852077, 183879649, 184904831
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OFFSET
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1,1
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LINKS
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EXAMPLE
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The 3 iterations: 3893257 --> 1110110110100000001001 --> ... --> ... are prime.
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PROG
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(PARI) isok(n, nb=3) = {for (k=1, nb, b = binary(n); d = eval(subst(Pol(b), x, 10)); if (! isprime(d), return (0)); n = d; ); return (1); } \\ Michel Marcus, Apr 08 2015
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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