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Search: id:A106622
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| A106622 |
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Primes of the form r(r(r(n)+1)+1)+1, where A141468(n)=r(n)=n-th nonprime. |
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+0
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| 2, 17, 23, 31, 37, 47, 67, 71, 97, 101, 103, 109, 127, 131, 137, 139, 149, 151, 157, 163, 179, 191, 197, 199, 211, 223, 227, 233, 239, 241, 257, 263, 269, 271, 277, 281, 283, 311, 313, 331, 347, 349, 353, 359, 367, 373, 379, 389, 397, 401, 419, 431, 443, 449
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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If n=1, then
r(r(r(1)+1)+1)+1=r(r(0+1)+1)+1=r(r(1)+1)+1=r(0+1)+1=r(1)+1=0+1=1
(nonprime).
If n=2, then
r(r(r(2)+1)+1)+1=r(r(1+1)+1)+1=r(r(2)+1)+1=r(1+1)+1=r(2)+1=1+1=2=a(1).
If n=3, then
r(r(r(3)+1)+1)+1=r(r(4+1)+1)+1=r(r(5)+1)+1=r(8+1)+1=r(9)+1=14+1=15
(nonprime).
If n=4, then
r(r(r(4)+1)+1)+1=r(r(6+1)+1)+1=r(r(7)+1)+1=r(10+1)+1=r(11)+1=16+1=17=a(2).
If n=5, then
r(r(r(5)+1)+1)+1=r(r(8+1)+1)+1=r(r(9)+1)+1=r(14+1)+1=r(15)+1=22+1=23=a(3).
If n=6, then
r(r(r(6)+1)+1)+1=r(r(9+1)+1)+1=r(r(10)+1)+1=r(15+1)+1=r(16)+1=24+1=25
(nonprime).
If n=7, then
r(r(r(7)+1)+1)+1=r(r(10+1)+1)+1=r(r(11)+1)+1=r(16+1)+1=r(17)+1=25+1=26
(nonprime).
If n=8, then
r(r(r(8)+1)+1)+1=r(r(12+1)+1)+1=r(r(13)+1)+1=r(20+1)+1=r(21)+1=30+1=31=a(4).
If n=9, then
r(r(r(9)+1)+1)+1=r(r(14+1)+1)+1=r(r(15)+1)+1=r(22+1)+1=r(23)+1=33+1=34
(nonprime).
If n=10, then
r(r(r(10)+1)+1)+1=r(r(15+1)+1)+1=r(r(16)+1)+1=r(24+1)+1=r(25)+1=35+1=36
(nonprime)
If n=11, then
r(r(r(11)+1)+1)+1=r(r(16+1)+1)+1=r(r(17)+1)+1=r(25+1)+1=r(26)+1=36+1=37=a(5),
etc.
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CROSSREFS
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Cf. A000040, A141468.
Sequence in context: A157191 A006029 A126961 this_sequence A040992 A049550 A049574
Adjacent sequences: A106619 A106620 A106621 this_sequence A106623 A106624 A106625
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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), Aug 25 2008
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EXTENSIONS
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67 inserted, 73 removed, 227 and 233 inserted and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008
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