%I #10 Oct 15 2013 04:06:02
%S 1,3,4,4,3,3,4,4,3,1,0,0,1,1,0,0,1,3,4,4,5,7,10,12,13,13,14,16,17,17,
%T 16,16,17,19,20,20,21,23,26,28,29,31,34,38,41,43,44,46,49,51,52,52,53,
%U 55,56,56,55,55,56,58,59,59,60,62,65,67,68,68,69,71,72,72,71,71,72,72,71
%N A Von Koch curve related to the Golden ratio.
%H Benoit Cloitre, <a href="/A085005/a085005.png">Plot of a(n) for n=1 up to 1362772</a>
%F a(n)=(-1)*sum(i=1, n, sum(j=1, i, (-1)^floor(j*(1+sqrt(5))/2)))
%F a(n) = 2*sum(k = 1, n, sum(i = 1, k, b(i)))-n*(n+1)/2, where b(k) = floor(phi*k)-2*floor(phi*k/2)
%o (PARI) a(n)=(-1)*sum(i=1,n,sum(j=1,i,(-1)^floor(j*(1+sqrt(5))/2)))
%Y Cf. A083035, A083036, A083037, A083038, A085002, A085003, A085004.
%Y Cf. A094200, A094201.
%K nonn
%O 1,2
%A _Benoit Cloitre_, Jun 17 2003