A244483 a(0)=3, a(1)=1, a(2)=0; thereafter a(n) = a(n-1-a(n-1))+a(n-2-a(n-2)) unless a(n-1) <= n-1 or a(n-2) <= n-2 in which case the sequence terminates.

3, 1, 0, 3, 3, 4, 2, 4, 6, 3, 2, 8, 9, 6, 7, 8, 8, 10, 10, 10, 9, 11, 10, 11, 18, 11, 9, 17, 12, 10, 18, 19, 18, 16, 17, 20, 18, 18, 20, 20, 20, 19, 19, 21, 21, 21, 29, 28, 20, 22, 29, 28, 22, 29, 36, 28, 27, 27, 28, 36, 29, 30, 38, 37, 27, 27, 38, 32, 32, 38, 37, 35, 34, 38, 40, 37, 37, 40, 38, 38, 39

Offset

0,1

References

Higham, Jeff and Tanny, Stephen, A tamely chaotic meta-Fibonacci sequence. Twenty-third Manitoba Conference on Numerical Mathematics and Computing (Winnipeg, MB, 1993). Congr. Numer. 99 (1994), 67-94.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Index entries for Hofstadter-type sequences

Maple

f := proc(n) option remember;
    if n=0 then 3
    elif n=1 then 1
    elif n=2 then 0
    else
    f(n-1-f(n-1))+f(n-2-f(n-2));
    fi;
end proc;
[seq(f(n), n=0..80)];

Prog

(Haskell)
a244483 n = a244483_list !! n
a244483_list = 3 : 1 : 0 : zipWith (+) xs (tail xs)
   where xs = map a244483 $ zipWith (-) [1..] $ tail a244483_list
-- Reinhard Zumkeller, Jul 07 2014

Crossrefs

See A006949 for overview of sequences produced by this recurrence and various initial conditions.

Sequence in context: A256759 A336090 A255123 * A292727 A049403 A104556

Adjacent sequences: A244480 A244481 A244482 * A244484 A244485 A244486

Keyword

nonn

Author

N. J. A. Sloane, Jul 03 2014

Status

approved