This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A086843 #11 Jul 01 2025 19:24:29 %S A086843 1,7,11,13,17,21,23,27,33,37,39,43,49,53,59,63,65,69,75,79,81,85,91, %T A086843 95,101,105,107,111,117,121,123,127,131,133,137,143,147,149,153,159, %U A086843 163,169,173,175,179,185,189,191,195,199,201,205,211,215,217,221,227,231 %N A086843 Odd numbers m such that the sequence defined by b(1) = m; for k>1, b(k) = floor(phi*b(k-1)), where phi = (1 + sqrt(5))/2, contains only odd numbers. %F A086843 Observation : a(n+1)-a(n) = 2, 4 or 6 for every n, a(n)=4n+O(1) and more precisely it seems that abs(a(n)-4n)<=7. Is the sequence a(n)-4n ultimately periodic ? _Benoit Cloitre_, Aug 10 2003 %e A086843 For m = 1 we get 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... %e A086843 For m = 7 we get 7, 11, 17, 27, 43, 69, 111, 179, 289, 467, 755, ... %Y A086843 Cf. A086844. %K A086843 nonn %O A086843 1,2 %A A086843 _Philippe Deléham_, Aug 09 2003