A258022 Nonnegative integers n with property that when starting from x=n, the map x -> floor(tan(x)) reaches [the fixed point] 0 (or any other integer less than 1 if such negative fixed points exist).

0, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81

Offset

1,2

Comments

Integers n >= 0 for which A258021(n) <= 0.

Natural numbers n such that the iteration of the function floor(tan(k)) applied to n eventually reaches [the fixed point] 0 (or less, if such negative fixed points exist), where k is interpreted as k radians. - Daniel Forgues, May 26 2015.

V.J. Pohjola conjectures that the only fixed points of function k -> floor(tan(k)) are 0 and 1.

Links

Table of n, a(n) for n=1..74.

Prog

(Scheme, with Antti Karttunen's IntSeq-library)
(define A258022 (MATCHING-POS 1 0 (lambda (n) (<= (A258021 n) 0))))

Crossrefs

Cf. A258024 (complement provided that function x -> floor(tan(x)) does not form cycles larger than one).

Cf. A000503, A258020, A258021.

Sequence in context: A004723 A293754 A242410 * A333638 A089590 A052406

Adjacent sequences: A258019 A258020 A258021 * A258023 A258024 A258025

Keyword

nonn

Author

V.J. Pohjola & Antti Karttunen, May 24 2015

Status

approved