Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #34 Dec 15 2023 15:10:12
%S 0,1,3,5,7,9,10,12,14,16,18,19,21,23,25,27,28,30,32,34,36,37,39,41,43,
%T 45,46,48,50,52,54,55,57,59,61,63,64,66,68,70,72,73,75,77,79,81,82,84,
%U 86,88,90,91,93,95,97,99,100,102,104,106,108,109,111,113,115,117,118,120,122,124,126,127,129,131,133,135,136,138,140,142,144,145,147,149,151,153,154,156,158,160,162,163,165,167,169,171,172,174,176,178,180,181,183,185,187,189,191
%N A Beatty sequence: a(n)=floor(n*p) where p=2*cos(Pi/7)=A160389.
%C Beatty sequence of the shorter diagonal (A160389) in a regular heptagon with sidelength 1.
%C Complement of Beatty sequence A262773 of the longer diagonal (A231187) in a regular heptagon with sidelength 1.
%C First 106 terms agree with A187318, but A187318(106)=190 while A262770(106)=191.
%H Peter Steinbach, <a href="http://www.jstor.org/stable/2691048">Golden Fields: A Case for the Heptagon</a>, Mathematics Magazine, Vol. 70, No. 1, Feb. 1997.
%H <a href="/index/Be#Beatty">Index entries for sequences related to Beatty sequences</a>
%t Table[Floor[2 n Cos[Pi/7]], {n, 0, 106}] (* _Michael De Vlieger_, Oct 05 2015 *)
%o (Octave) p=roots([1,-1,-2,1])(1); a(n)=floor(p*n)
%o (PARI) a(n) = floor(n*2*cos(Pi/7)); \\ _Michel Marcus_, Oct 05 2015
%Y Complement of A262773.
%Y Initially agrees with A187318 (because 2*cos(Pi/7) is close to 9/5).
%K nonn
%O 0,3
%A _Patrick D McLean_, Sep 30 2015