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 A106622 Primes of the form r(r(r(n)+1)+1)+1, where A141468(n)=r(n)=n-th nonprime. 0
 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; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..54. EXAMPLE 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. CROSSREFS Cf. A000040, A141468. Sequence in context: A006029 A332094 A126961 * A040992 A049550 A049574 Adjacent sequences: A106619 A106620 A106621 * A106623 A106624 A106625 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Aug 25 2008 EXTENSIONS 67 inserted, 73 removed, 227 and 233 inserted and extended by R. J. Mathar, Sep 05 2008 STATUS approved

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Last modified December 9 12:57 EST 2023. Contains 367690 sequences. (Running on oeis4.)