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 A119655 a(0) = a(1) = 0. a(n) = number of earlier terms of the sequence which are not coprime to n. 1
 0, 0, 2, 2, 4, 2, 6, 2, 8, 3, 9, 2, 12, 2, 12, 7, 13, 2, 16, 2, 16, 8, 18, 2, 22, 2, 23, 8, 24, 2, 27, 2, 26, 11, 27, 3, 32, 2, 29, 14, 30, 2, 38, 2, 35, 14, 36, 2, 42, 7, 39, 16, 41, 2, 46, 6, 45, 19, 43, 2, 51, 2, 44, 24, 46, 8, 57, 2, 50, 24, 55, 2, 61, 2, 53, 25, 55, 13, 64, 2, 60 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Diana L. Mecum, Table of n, a(n) for n = 0..1199 EXAMPLE Among the first 20 terms of the sequence there are 8 terms which are not coprime to 21 - a(0)=0, a(1)=0, a(6)=6, a(9)=3, a(10)=9, a(12)=12, a(14)=12 and a(15)=7. So a(21) = 8. MATHEMATICA a = {0, 0}; Do[AppendTo[a, Length[Select[a, GCD[Length[a], # ] > 1 &]]], {70}]; a (* Stefan Steinerberger, Oct 16 2007 *) CROSSREFS Sequence in context: A118982 A129457 A275365 * A083260 A284011 A275468 Adjacent sequences:  A119652 A119653 A119654 * A119656 A119657 A119658 KEYWORD nonn AUTHOR Leroy Quet, Jul 28 2006 EXTENSIONS More terms from Stefan Steinerberger, Oct 16 2007 More terms from Diana L. Mecum, Aug 15 2008 STATUS approved

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Last modified January 25 08:36 EST 2022. Contains 350565 sequences. (Running on oeis4.)