%I #5 May 20 2014 14:54:16
%S 4,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,
%T 4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,5,5,4,5,5,5,
%U 5,4,5,5,5,5,5,4,5,5,5,5
%N A self-generating sequence: there are a(n) (k+1)'s between successive k's, where k=4.
%p f := proc(n,k) floor(n*(k+sqrt(k^2+4*k))/2)-floor((n-1)*(k+sqrt(k^2+4*k))/2); end; (with k=4)
%Y Cf. A001468, A007538.
%K nonn
%O 1,1
%A _Jonas Wallgren_