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Search: id:A080165
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| A080165 |
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Primes having initial digits "10" in binary representation. |
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+0
4
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| 2, 5, 11, 17, 19, 23, 37, 41, 43, 47, 67, 71, 73, 79, 83, 89, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 521, 523, 541, 547, 557, 563
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Also primes that terminate at 4,2,1 in the x-1 problem: Repeat, if x is even divide by 2 else subtract 1, until 4 is reached. - Cino Hilliard, Mar 27 2003
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EXAMPLE
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A000040(15)=47 -> '101111' therefore 47 is a term.
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PROGRAM
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(PARI) pxnm1(n, p) = { forprime(x=2, n, p1 = x; while(p1>1, if(p1%2==0, p1/=2, p1 = p1*p-1; ); if(p1 == 4, break); ); if(p1 == 4, print1(x" ")) ) }
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CROSSREFS
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Cf. A004676, A080166, A080167.
Cf. A080167.
Adjacent sequences: A080162 A080163 A080164 this_sequence A080166 A080167 A080168
Sequence in context: A009770 A132121 A070957 this_sequence A063535 A091653 A136244
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KEYWORD
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nonn,base
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 03 2003
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