OFFSET
1,2
COMMENTS
To built the sequence start from the infinite Fibonacci word b(k)=floor(k/phi)-floor((k-1)/phi) for k>=1 giving 0,1,0,1,1,0,1,0,1,1,0,1,1,0,1,0,1,1,..... Then replace each 0 by the block {5,6,6} and each 1 by the block {7, 6, 6, 7, 6}. Append the initial string {1,2,3,4}.
REFERENCES
Benoit Cloitre, On properties of irrational numbers related to the floor function, in preparation, 2005.
PROG
(PARI) F(x)=floor((1+sqrt(5))/2*floor((-1+sqrt(5))/2*x)); a(n)=n-F(F(F(F(n))))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, Sep 02 2005
STATUS
approved