

A258203


Natural numbers n that have the property that starting from k = n, the fixed point of the map k > floor(tan(k)) is strictly positive, and the smallest number encountered during the iteration is also strictly positive.


4



1, 4, 23, 26, 45, 48, 67, 70, 89, 92, 105, 111, 114, 127, 133, 136, 149, 155, 158, 171, 177, 180, 183, 193, 199, 202, 205, 215, 221, 224, 227, 243, 246, 249, 265, 268, 271, 290, 293, 300, 312, 315, 334, 337, 344, 356, 359, 378, 381, 400, 403, 422, 425, 444, 447, 460, 466, 469, 482, 488, 491, 504, 510, 513
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

Natural numbers n for which A258021(n) > 0 and A258201(n) > 0, or in other words, numbers n such that starting from k = n, the repeated application of map k > floor(tan(k)) reaches 1 (or any other of strictly positive fixed points, whose existence however remains hypothetical) without ever visiting any negative number.


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A258203 (MATCHINGPOS 1 1 (lambda (n) (and (> (A258021 n) 0) (> (A258201 n) 0)))))


CROSSREFS

Complement of A258202 in A258024.
Cf. A258021, A258201.
Sequence in context: A115989 A016485 A258024 * A293698 A160613 A131545
Adjacent sequences: A258200 A258201 A258202 * A258204 A258205 A258206


KEYWORD

nonn


AUTHOR

Antti Karttunen & Daniel Forgues, May 26 2015


STATUS

approved



