cp's OEIS Frontend

A373229 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 9; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 9.

%I A373229 #11 May 31 2024 06:43:55
%S A373229 1,2,3,4,5,6,7,8,9,6,10,11,12,9,13,14,15,12,16,17,18,15,19,20,17,22,
%T A373229 18,22,24,25,22,21,29,28,22,24,34,27,29,28,32,27,37,33,31,34,35,36,34,
%U A373229 36,41,36,41,36,41,43,41,43,40,48,42,41,46,46,52,43,51,46,53,51,46,56,48
%N A373229 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 9; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 9.
%C A373229 Similar to A278055 but with different starting values.
%C A373229 Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n.
%C A373229 a(n) exists for n <= 3*10^7.
%H A373229 Nathan Fox, <a href="/A373229/b373229.txt">Table of n, a(n) for n = 1..10000</a>
%t A373229 a[n_] := a[n] = If[0 < n < 10, n, a[n-a[n-1]] + a[n-a[n-2]] + a[n-a[n-3]]];
%t A373229 Array[a, 100] (* _Paolo Xausa_, May 31 2024 *)
%Y A373229 Cf. A005185, A278055, A373227, A373228, A373230, A373231, A373232, A373233.
%Y A373229 Similar sequences based on the Q-recurrence: A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.
%K A373229 nonn
%O A373229 1,2
%A A373229 _Nathan Fox_, May 28 2024