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 A118073 Nonprimes of the form r(r(r(r(r(r(n)+1)+1)+1)+1)+1)+1, where A141468(n)=r(n)=n-th nonprime. 0
 1, 49, 52, 70, 86, 91, 94, 95, 116, 118, 121, 124, 125, 133, 135, 154, 160, 161, 162, 172, 175, 177, 185, 195, 203, 206, 207, 208, 219, 222, 225, 236, 248, 250, 253, 255, 261, 262, 267, 275, 286, 288, 298, 300, 301, 306, 315, 319, 321, 323, 326, 327, 328, 329 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE If n = 1, then r(r(r(r(r(r(1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(0+1)+1)+1)+1)+1)+1 = r(r(r(r(r(1)+1)+1)+1)+1)+1 = r(r(r(r(0+1)+1)+1)+1)+1 = r(r(r(r(1)+1)+1)+1)+1 = r(r(r(0+1)+1)+1)+1 = 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 = a(1). If n = 2, then r(r(r(r(r(r(2)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(1+1)+1)+1)+1)+1)+1 = r(r(r(r(r(2)+1)+1)+1)+1)+1 = r(r(r(r(1+1)+1)+1)+1)+1 = r(r(r(r(2)+1)+1)+1)+1 = r(r(r(1+1)+1)+1)+1 = 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 (prime). If n = 3, then r(r(r(r(r(r(3)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(4+1)+1)+1)+1)+1)+1 = r(r(r(r(r(5)+1)+1)+1)+1)+1 = r(r(r(r(8+1)+1)+1)+1)+1 = r(r(r(r(9)+1)+1)+1)+1 = r(r(r(14+1)+1)+1)+1 = r(r(r(15)+1)+1)+1 = r(r(22+1)+1)+1 = r(r(23)+1)+1 = r(33+1)+1 = r(34)+1 = 48+1 = 49 = a(2). If n = 4, then r(r(r(r(r(r(4)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(6+1)+1)+1)+1)+1)+1 = r(r(r(r(r(7)+1)+1)+1)+1)+1 = r(r(r(r(10+1)+1)+1)+1)+1 = r(r(r(r(11)+1)+1)+1)+1 = r(r(r(16+1)+1)+1)+1 = r(r(r(17)+1)+1)+1 = r(r(25+1)+1)+1 = r(r(26)+1)+1 = r(36+1)+1 = r(37)+1 = 51+1 = 52 = a(3). If n = 5, then r(r(r(r(r(r(5)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(8+1)+1)+1)+1)+1)+1 = r(r(r(r(r(9)+1)+1)+1)+1)+1 = r(r(r(r(14+1)+1)+1)+1)+1 = r(r(r(r(15)+1)+1)+1)+1 = r(r(r(22+1)+1)+1)+1 = r(r(r(23)+1)+1)+1 = r(r(33+1)+1)+1 = r(r(34)+1)+1 = r(48+1)+1 = r(49)+1 = 66+1 = 67 (prime). If n = 6, then r(r(r(r(r(r(6)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(9+1)+1)+1)+1)+1)+1 = r(r(r(r(r(10)+1)+1)+1)+1)+1 = r(r(r(r(15+1)+1)+1)+1)+1 = r(r(r(r(16)+1)+1)+1)+1 = r(r(r(24+1)+1)+1)+1 = r(r(r(25)+1)+1)+1 = r(r(35+1)+1)+1 = r(r(36)+1)+1 = r(50+1)+1 = r(51)+169+1 = 70 = a (4). If n = 7, then r(r(r(r(r(r(7)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(10+1)+1)+1)+1)+1)+1 = r(r(r(r(r(11)+1)+1)+1)+1)+1 = r(r(r(r(16+1)+1)+1)+1)+1 = r(r(r(r(17)+1)+1)+1)+1 = r(r(r(25+1)+1)+1)+1 = r(r(r(26)+1)+1)+1 = r(r(36+1)+1)+1 = r(r(37)+1)+1 = r(51+1)+1 = r(52)+1 = 70+1 = 71 (prime). If n = 8, then r(r(r(r(r(r(8)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(12+1)+1)+1)+1)+1)+1 = r(r(r(r(r(13)+1)+1)+1)+1)+1 = r(r(r(r(20+1)+1)+1)+1)+1 = r(r(r(r(21)+1)+1)+1)+1 = r(r(r(30+1)+1)+1)+1 = r(r(r(31)+1)+1)+1 = r(r(44+1)+1)+1 = r(r(45)+1)+1 = r(62+1)+1 = r(63)+1 = 85+1 = 86 = a (5). If n = 9, then r(r(r(r(r(r(9)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(14+1)+1)+1)+1)+1)+1 = r(r(r(r(r(15)+1)+1)+1)+1)+1 = r(r(r(r(22+1)+1)+1)+1)+1 = r(r(r(r(23)+1)+1)+1)+1 = r(r(r(33+1)+1)+1)+1 = r(r(r(34)+1)+1)+1 = r(r(48+1)+1)+1 = r(r(49)+1)+1 = r(66+1)+1 = r(67)+1 = 90+1 = 91 = a(6), etc. CROSSREFS Cf. A000040, A141468. Sequence in context: A042199 A257443 A020276 * A043300 A304008 A305358 Adjacent sequences:  A118070 A118071 A118072 * A118074 A118075 A118076 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Aug 25 2008 EXTENSIONS 165 removed, 206 added, 257 removed by R. J. Mathar, Sep 05 2008 STATUS approved

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Last modified December 12 18:24 EST 2018. Contains 318081 sequences. (Running on oeis4.)