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Search: id:A141639
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| A141639 |
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Primes of the form c(c(i)-3)-3, where A002808(i)=c(i)=i-th composite. |
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+0
1
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| 5, 7, 11, 13, 17, 19, 31, 37, 41, 43, 53, 59, 61, 71, 73, 79, 83, 89, 97, 103, 109, 113, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 251, 257, 263, 269, 271, 281, 293, 307, 313, 317, 337, 347, 349, 353, 359
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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If i=1, then
c(c(1)-3)-3=c(4-3)-3=4-3=1 (nonprime).
If i=2, then
c(c(2)-3)-3=c(6-3)-3=c(3)-3=8-3=5=a(1).
If i=3, then
c(c(3)-3)-3=c(8-3)-3=c(5)-3=10-3=7=a(2).
If i=4, then
c(c(4)-3)-3=c(9-3)-3=c(6)-3=12-3=9 (nonprime).
If i=5, then
c(c(5)-3)-3=c(10-3)-3=c(7)-3=14-3=11=a(3),
etc.
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CROSSREFS
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Cf. A002808, A000040.
Sequence in context: A098420 A093495 A093496 this_sequence A024891 A136144 A086304
Adjacent sequences: A141636 A141637 A141638 this_sequence A141640 A141641 A141642
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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), Sep 03 2008
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EXTENSIONS
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43, 59, 73, 227, 229, 347, 367 inserted by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008
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