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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
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
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.
Sequence in context: A115989 A016485 A258024 * A293698 A160613 A131545
KEYWORD
nonn
AUTHOR
STATUS
approved