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)).

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

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