%I #20 Mar 14 2020 18:51:43
%S 1,1,0,1,1,2,3,0,3,3,6,3,9,2,11,3,0,3,3,6,9,2,11,0,11,11,6,17,11,9,20,
%T 5,25,3,28,7,5,12,17,6,23,10,0,10,10,20,3,23,0,23,23,17,4,21,25,15,40,
%U 1,41,4,45,15,12,27,1,28,29,18,47,19,14,33,7,40
%N a(1) = a(2) = 1; a(n) = (a(n-1) + a(n-2)) mod (n - a(n-1)).
%C Performing the modulus operation, the smallest nonnegative residue is to be taken.
%C a(A226483(n)) = n and a(m) <> n for m < A226483(n). - _Reinhard Zumkeller_, Jun 09 2013
%H Reinhard Zumkeller, <a href="/A224909/b224909.txt">Table of n, a(n) for n = 1..10000</a>
%e a(8) = (a(7) + a(6)) mod (8 - a(7)) = (2+3) mod (8-3) = 5 mod 5 = 0.
%t a[1]=1; a[2]=1; a[n_] := a[n] = Mod[a[n-1] + a[n-2], n - a[n-1]]; Array[a, 74] (* _Giovanni Resta_, Jun 08 2013 *)
%t nxt[{n_, a_, b_}] := {n + 1, b, Mod[a + b, n + 1 - b]}; NestList[nxt,{2,1,1},80][[All,2]] (* _Harvey P. Dale_, Mar 14 2020 *)
%o (Haskell)
%o a224909 n = a224909_list !! (n-1)
%o a224909_list = 1 : 1 : zipWith mod
%o (zipWith (+) a224909_list $ tail a224909_list)
%o (zipWith (-) [3..] $ tail a224909_list)
%o -- _Reinhard Zumkeller_, Jun 09 2013
%K nonn
%O 1,6
%A _David S. Newman_, Apr 19 2013
%E a(31)-a(74) from _Giovanni Resta_, Jun 08 2013