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Search: id:A140891
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| A140891 |
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Binary encoding of the prime-ness of the 6 integers r+14*n with remainder r=1, 3, 5, 9, 11 or 13. |
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+0
1
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| 9, 49, 20, 42, 41, 20, 27, 33, 62, 10, 39, 21, 11, 39, 60, 30, 49, 28, 43, 41, 28, 31, 49, 55, 14, 53, 53, 42, 51, 29, 14, 51, 22, 58, 45, 22, 59, 57, 55, 46, 37, 29, 11, 43, 60, 14, 53, 60, 42, 59, 54, 27, 43, 54, 26, 61, 29, 15, 39, 28, 31, 49, 23, 58, 47, 54, 27, 53, 62, 42
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Classify all integers 14n+r with r= 1, 3, 5, 9, 11 or 13 as nonprime or prime and assign hit positions 0=LSB, 1, 2, 3, 4, 5=MSB to the 6 remainders in the same order. Rais the bit if 14n+r is nonprime, erase it if 14n+r is prime.
The sequence interprets this as a number in base 2 and shows the decimal representation.
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EXAMPLE
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For n=2, the 6 numbers 29 (r=1), 31 (r=3), 33 (r=5), 37 (r=9), 39 (r=11) and 41 (r=13) are prime, prime, nonprime, prime, nonprime, prime, which is rendered into the binary 001010 = 2^2+2^4=4+16=20=a(2).
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MATHEMATICA
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f[n_]:=FromDigits[1-Boole[PrimeQ[({13, 11, 9, 5, 3, 1}+14n)]], 2]; Table[f[n], {n, 0, 100}] (*Chandler*)
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CROSSREFS
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Cf. A105052, A140387.
Sequence in context: A115053 A073584 A007037 this_sequence A072461 A012260 A133478
Adjacent sequences: A140888 A140889 A140890 this_sequence A140892 A140893 A140894
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KEYWORD
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nonn
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jul 07 2008
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EXTENSIONS
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Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 20 2009
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