The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A258020 Number of steps to reach a fixed point with map x -> floor(tan(x)) when starting the iteration with the initial value x = n. 5
 0, 0, 2, 5, 1, 5, 5, 1, 6, 5, 1, 2, 5, 1, 2, 5, 1, 6, 4, 1, 3, 4, 1, 1, 2, 5, 1, 5, 5, 1, 6, 5, 1, 6, 5, 1, 2, 5, 1, 6, 4, 1, 3, 4, 1, 1, 2, 5, 1, 5, 5, 1, 6, 5, 1, 4, 5, 1, 7, 5, 1, 6, 4, 1, 3, 4, 1, 1, 2, 5, 1, 5, 5, 1, 2, 5, 1, 7, 5, 1, 6, 5, 1, 6, 4, 1, 3, 4, 1, 1, 4, 5, 1, 2, 5, 1, 2, 5, 1, 5, 5, 1, 6, 5, 1, 2, 4, 1, 3, 4, 1, 1, 4, 5, 1, 2, 5, 1, 2, 5, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Note that this sequence lists such values only for nonnegative integers, although the function is defined in all Z. LINKS Antti Karttunen, Table of n, a(n) for n = 0..10000 FORMULA If n is equal to floor(tan(n)) then a(n) = 0; for any other n (positive or negative): a(n) = 1 + a(floor(tan(n))). [The domain of the recurrence is whole Z.] EXAMPLE The only known fixed points of function x -> floor(tan(x)) are 0 and 1 (and it is conjectured there are no others), thus a(0) = a(1) = 0. For n=2, we get tan(2) = -2.185, thus floor(tan(2)) = -3. tan(-3) = 0.1425, thus floor(tan(-3)) = 0, and we have reached a fixed point in two steps, thus a(2) = 2. PROG (Scheme) (define (A258020 n) (if (= n (floor->exact (tan n))) 0 (+ 1 (A258020 (floor->exact (tan n)))))) CROSSREFS Cf. A000503, A258021, A258022, A258024, A258201. Sequence in context: A229982 A327123 A289848 * A021803 A077382 A046527 Adjacent sequences:  A258017 A258018 A258019 * A258021 A258022 A258023 KEYWORD nonn AUTHOR Antti Karttunen, May 24 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 24 06:56 EDT 2021. Contains 346273 sequences. (Running on oeis4.)