OFFSET
1,2
FORMULA
Recurrence: a(4n+1) = (n mod 3) + 1, a(4n+2) = (n+1 mod 3) + 1, a(4n+3) = f(a(2n+1)), a(4n+4) = f(a(2n+2)), where f(1)=1, f(2)=3, f(3)=2.
EXAMPLE
The solution to the 3-disk puzzle is (1,2),(1,3),(2,3),(1,2),(3,1),(3,2),(1,2), therefore a(1) through a(7) are the same numbers in sequence.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Dec 09 2004
STATUS
approved