cp's OEIS Frontend

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.

%I A258203 #14 Jun 05 2015 03:56:41
%S A258203 1,4,23,26,45,48,67,70,89,92,105,111,114,127,133,136,149,155,158,171,
%T A258203 177,180,183,193,199,202,205,215,221,224,227,243,246,249,265,268,271,
%U A258203 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
%N 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.
%C A258203 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.
%H A258203 Antti Karttunen, <a href="/A258203/b258203.txt">Table of n, a(n) for n = 1..10000</a>
%o A258203 (Scheme, with _Antti Karttunen_'s IntSeq-library)
%o A258203 (define A258203 (MATCHING-POS 1 1 (lambda (n) (and (> (A258021 n) 0) (> (A258201 n) 0)))))
%Y A258203 Complement of A258202 in A258024.
%Y A258203 Cf. A258021, A258201.
%K A258203 nonn
%O A258203 1,2
%A A258203 _Antti Karttunen_ & _Daniel Forgues_, May 26 2015