cp's OEIS Frontend

A067017 Start with a(0)=1, a(1)=4, a(2)=3, a(3)=2; for n>=3, a(n+1) = mex_i (a(i)+a(n-i)), where mex means smallest nonnegative missing number.

%I A067017 #9 Jul 13 2013 12:02:42
%S A067017 1,4,3,2,0,0,0,0,0,5,1,1,1,1,1,6,2,2,0,0,0,0,0,5,1,1,1,1,1,6,2,2,0,0,
%T A067017 0,0,0,5,1,1,1,1,1,6,2,2,0,0,0,0,0,5,1,1,1,1,1,6,2,2,0,0,0,0,0,5,1,1,
%U A067017 1,1,1,6,2,2,0,0,0,0,0,5,1,1,1,1,1,6,2,2,0,0,0,0,0,5,1,1,1,1,1,6,2,2,0,0,0
%N A067017 Start with a(0)=1, a(1)=4, a(2)=3, a(3)=2; for n>=3, a(n+1) = mex_i (a(i)+a(n-i)), where mex means smallest nonnegative missing number.
%D A067017 R. K. Guy, Unsolved Problems in Number Theory, E27.
%H A067017 Reinhard Zumkeller, <a href="/A067017/b067017.txt">Table of n, a(n) for n = 0..10000</a>
%o A067017 (Haskell)
%o A067017 import Data.List ((\\))
%o A067017 a067017 n = a067017_list !! n
%o A067017 a067017_list =  [1,4,3,2] ++ f [2,3,4,1] where
%o A067017   f xs = mexi : f (mexi : xs) where
%o A067017     mexi = head $ [0..] \\ zipWith (+) xs (reverse xs)
%o A067017 -- _Reinhard Zumkeller_, May 05 2012
%Y A067017 Cf. A067016, A067018.
%K A067017 nonn,easy
%O A067017 0,2
%A A067017 _N. J. A. Sloane_, Feb 17 2002
%E A067017 More terms from _John W. Layman_, Feb 20 2002