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.
%I A373232 #11 May 31 2024 22:12:36 %S A373232 1,2,3,4,5,6,7,8,9,10,11,12,6,13,14,15,9,16,17,18,12,19,20,21,15,22, %T A373232 23,17,25,18,25,27,28,22,21,35,31,19,30,31,40,25,31,27,47,31,33,24,46, %U A373232 35,43,24,51,32,49,33,44,37,55,40,39,46,50,44,43,54,47,40,58,50,43,57,53 %N A373232 Relative of Hofstadter Q-sequence: a(n) = 0 for n <= 0, a(n) = n for 1 <= n <= 12; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 12. %C A373232 Similar to A278055 but with different starting values. %C A373232 a(45) = 47. This is the smallest index for which a(n) > n. So, without the condition that a(n) = 0 for n <= 0, this sequence would be finite and have exactly 45 terms. %C A373232 Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n. %C A373232 a(n) exists for n <= 3*10^7. %H A373232 Nathan Fox, <a href="/A373232/b373232.txt">Table of n, a(n) for n = 1..10000</a> %t A373232 a[n_] := a[n] = Which[n < 1, 0, n < 13, n, True, a[n-a[n-1]] + a[n-a[n-2]] + a[n-a[n-3]]]; Array[a, 100] (* _Paolo Xausa_, May 31 2024 *) %Y A373232 Cf. A005185, A278055, A373227, A373228, A373229, A373230, A373231, A373233. %Y A373232 Similar sequences based on the Q-recurrence: A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065. %K A373232 nonn %O A373232 1,2 %A A373232 _Nathan Fox_, May 28 2024