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 A261273 Take the list of positive rationals {R(n): n>=1} in the order defined by Calkin and Wilf (Recounting the Rationals, 1999); a(n) = denominator of R(prime(n)). 0
 2, 1, 2, 1, 2, 3, 4, 3, 2, 4, 1, 7, 8, 5, 2, 8, 4, 5, 5, 4, 11, 3, 8, 12, 9, 12, 5, 8, 11, 10, 1, 6, 14, 9, 18, 7, 13, 11, 8, 18, 12, 19, 2, 11, 16, 7, 13, 3, 10, 17, 18, 4, 13, 6, 8, 6, 16, 5, 23, 22, 13, 26, 17, 10, 23, 16, 19, 29, 18, 23, 22, 12, 7, 25, 11, 2, 20, 23, 26, 29, 18, 31, 8, 27, 11, 14, 16, 27, 24, 7, 18, 4, 9, 14, 11, 6, 8, 20, 13, 21, 19, 32, 22, 30, 17, 23, 26, 40, 18, 43, 7, 41, 44, 27, 13, 20, 17, 14, 36, 30, 49, 37, 50, 34, 31, 28, 39, 12, 19, 33, 23, 16, 9, 31, 24, 15, 24, 25, 30, 50, 31, 46, 17, 22, 27, 18, 55, 50, 29, 8, 41, 36, 25, 14, 23, 10, 17, 32, 47, 40, 26, 34, 13, 22, 32, 14, 5, 27 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The list of rationals {R(n)} is essentially given by A002487(n)/A002487(n+1). LINKS Table of n, a(n) for n=1..168. N. Calkin and H. S. Wilf, Recounting the rationals, Amer. Math. Monthly, 107 (No. 4, 2000), pp. 360-363. CROSSREFS Companion sequence to A261179. Sequence in context: A317586 A303780 A234022 * A097454 A139803 A058746 Adjacent sequences: A261270 A261271 A261272 * A261274 A261275 A261276 KEYWORD nonn AUTHOR James Kirk Winkler, Aug 13 2015 STATUS approved

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Last modified September 13 08:04 EDT 2024. Contains 375889 sequences. (Running on oeis4.)