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 A001598 Number of terms in {b(1)..b(n)} relatively prime to b(n), where b(n) = A001597(n). (Formerly M2244 N0891) 1
 1, 1, 1, 3, 2, 5, 5, 4, 2, 9, 5, 8, 5, 13, 12, 8, 5, 17, 8, 6, 11, 14, 11, 23, 7, 23, 26, 11, 16, 14, 15, 31, 10, 28, 16, 24, 15, 37, 9, 39, 16, 20, 27, 20, 31, 14, 43, 47, 23, 32, 20, 51, 17, 14, 54, 24, 30, 28, 27, 40, 57, 61, 20, 56, 26, 42, 30, 28, 68, 22 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 REFERENCES N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 H. W. Gould, Problem H-170, Fib. Quart., 8 (1970), p. 268. MATHEMATICA nn = 10^4; t = Join[{1}, Union[Flatten[Table[n^i, {i, Prime[Range[PrimePi[Log[2, nn]]]]}, {n, 2, nn^(1/i)}]]]]; Table[Count[GCD[Take[t, n], t[[n]]], 1], {n, Length[t]}] (* T. D. Noe, Aug 09 2012 *) CROSSREFS Sequence in context: A132778 A182289 A127738 * A141297 A303917 A186929 Adjacent sequences:  A001595 A001596 A001597 * A001599 A001600 A001601 KEYWORD nonn,easy AUTHOR EXTENSIONS a(1) added by T. D. Noe, Aug 09 2012 STATUS approved

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Last modified April 16 05:26 EDT 2021. Contains 343030 sequences. (Running on oeis4.)