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Search: id:A074831
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| A074831 |
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Number of binary reversal primes less than 10^n. |
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+0
1
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| 3, 20, 101, 508, 3053, 20053, 141772, 1045600, 8038954
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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MathPages counts 1 as being a binary reversal prime whereas the title would exclude it, therefore their count exceeds this count by one.
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LINKS
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MathPages, Reflective and Cyclic Sets of Primes
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MATHEMATICA
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f[n_] := FromDigits[Reverse[IntegerDigits[n, 2]], 2]; NextPrim[n_] := Block[{k = n + 1}, While[ ! PrimeQ[k], k++ ]; k]; c = 0; k = 1; Do[ While[k = NextPrim[k]; k < 10^n, If[ PrimeQ[ f[k]], c++ ]]; k--; Print[c], {n, 16}]
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CROSSREFS
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Sequence in context: A092786 A015529 A000948 this_sequence A000917 A025535 A119693
Adjacent sequences: A074828 A074829 A074830 this_sequence A074832 A074833 A074834
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KEYWORD
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base,hard,more,nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 09 2002
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