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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 IntSeq-library)

(define A258203 (MATCHING-POS 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

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Last modified February 3 18:43 EST 2023. Contains 360044 sequences. (Running on oeis4.)