cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A373227 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 7; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 7.

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%I A373227 #15 May 31 2024 14:33:17
%S A373227 1,2,3,4,5,6,7,6,8,9,10,9,11,12,13,12,14,15,16,15,17,18,17,20,18,20,
%T A373227 22,21,21,22,26,25,23,24,28,26,29,26,31,30,32,28,34,30,37,29,38,35,37,
%U A373227 33,39,40,38,37,42,43,40,40,44,42,47,43,44,46,51,46,46,50,50,50,51,53,50
%N A373227 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 7; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 7.
%C A373227 Similar to A278055 but with different starting values.
%C A373227 Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n.
%C A373227 a(n) exists for n <= 3*10^7.
%H A373227 Nathan Fox, <a href="/A373227/b373227.txt">Table of n, a(n) for n = 1..10000</a>
%t A373227 a[n_] := a[n] = If[0 < n < 8, n, a[n-a[n-1]] + a[n-a[n-2]] + a[n-a[n-3]]];
%t A373227 Array[a, 100] (* _Paolo Xausa_, May 31 2024 *)
%Y A373227 Cf. A005185, A278055, A373228, A373229, A373230, A373231, A373232, A373233.
%Y A373227 Similar sequences based on the Q-recurrence: A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.
%K A373227 nonn
%O A373227 1,2
%A A373227 _Nathan Fox_, May 28 2024