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 A126134 Nonprimes of the form r(r(r(r(r(r(r(n)+1)+1)+1)+1)+1)+1)+1, where A141468(n) = r(n) = n-th nonprime. 0
 1, 91, 94, 95, 116, 121, 124, 125, 135, 154, 161, 162, 172, 175, 177, 195, 203, 206, 207, 208, 219, 222, 225, 236, 248, 250, 253, 261, 262, 267, 286, 288, 298, 301, 315, 319, 321, 323, 327, 328, 329, 334, 343, 345, 351, 357, 371, 375, 381, 387, 392, 396, 399 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE If n = 1, then r(r(r(r(r(r(r(1)+1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(r(0+1)+1)+1)+1)+1)+1)+1 = 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(r(2)+1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(r(1+1)+1)+1)+1)+1)+1)+1 = 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(r(3)+1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(r(4+1)+1)+1)+1)+1)+1)+1 = 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 = 4, then r(r(r(r(r(r(r(4)+1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(r(6+1)+1)+1)+1)+1)+1)+1 = 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 = 5, then r(r(r(r(r(r(r(5)+1)+1)+1)+1)+1)+1)+1 = r(r(r(r(r(r(8+1)+1)+1)+1)+1)+1)+1 = 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(2), etc. CROSSREFS Cf. A000040, A141468. Sequence in context: A129822 A321998 A020318 * A020223 A288453 A184034 Adjacent sequences:  A126131 A126132 A126133 * A126135 A126136 A126137 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Aug 25 2008 EXTENSIONS 160 removed, 165 removed, 203 added, 261 added, etc. by R. J. Mathar, Sep 05 2008 STATUS approved

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Last modified December 8 14:38 EST 2019. Contains 329865 sequences. (Running on oeis4.)