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)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen & Daniel Forgues, May 26 2015
STATUS
approved