%I #5 Sep 20 2023 05:51:16
%S 3,4,5,6,8,10,11,12,13,15,22,27,34,46,58,63,70,75,87,128,157,198
%N Companion sequence for A121501 used in a unit circle area approximation problem.
%C The pairs (n(k),m(k)):=(A121501(k),a(k)), k>=1, lead to a strictly decreasing sequence of relative errors E(n(k),m(k)) in the circle area approximation problem described in A121500. For each k=1,2,... the unit circle has inscribed n(k)-gon and circumscribed m(k)-gon.
%C For the sequence of relative errors E(n(k),m(k)), k=1..20 see the W. Lang link in A121501.
%F a(k) = A121500(A121501(k)), k>=1.
%e (n(k),m(k)) pairs (A121501(k),a(k)), for k=1..7: [3, 3], [5, 4], [6, 5], [8, 6], [11, 8], [14, 10], [15, 11].
%K nonn,more
%O 1,1
%A _Wolfdieter Lang_, Aug 16 2006