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 A038130 #40 Mar 21 2025 10:06:55
%S A038130 0,6,12,18,25,31,37,43,50,56,62,69,75,81,87,94,100,106,113,119,125,
%T A038130 131,138,144,150,157,163,169,175,182,188,194,201,207,213,219,226,232,
%U A038130 238,245,251,257,263,270,276,282,289,295,301,307,314,320,326,333,339,345
%N A038130 Beatty sequence for 2*Pi.
%C A038130 a(n) = floor[circumference of a circle of radius n]. - _Mohammad K. Azarian_, Feb 29 2008
%C A038130 This sequence consists of the nonnegative integers k satisfying sin(k) <= 0 and sin(k+1) >= 0; thus this sequence and A246388 partition A022844 (the Beatty sequence for Pi). - _Clark Kimberling_, Aug 24 2014
%H A038130 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BeattySequence.html">Beatty Sequence</a>.
%H A038130 <a href="/index/Be#Beatty">Index entries for sequences related to Beatty sequences</a>.
%F A038130 a(n) = floor(2*Pi*n).
%F A038130 a(n) = A004082(n+1) - 1. - _John W. Nicholson_, Mar 20 2025
%t A038130 Table[Floor[2 n*Pi], {n, 0, 100}] (* or *)
%t A038130 Select[Range[0, 628], Sin[#] <= 0 && Sin[# + 1] >= 0 &] (* _Clark Kimberling_, Aug 24 2014 *)
%Y A038130 Complement of A108586.
%Y A038130 For ceiling (2*Pi*n) see A004082.
%Y A038130 Cf. A022844, A140758, A108592, A246388.
%K A038130 nonn
%O A038130 0,2
%A A038130 _Felice Russo_
%E A038130 More terms from _Mohammad K. Azarian_, Feb 29 2008