A278058 - OEIS

%I #18 May 30 2024 06:56:14

%S 1,2,3,4,5,6,3,7,8,5,9,6,7,10,12,10,8,12,12,14,11,16,9,19,16,8,21,17,

%T 13,15,22,13,23,20,18,22,24,20,24,24,16,20,30,29,22,27,30,23,20,36,34,

%U 22,34,27,28,30,34,36,25,37,41,27,38,32,44,36,31

%N Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 6; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 6.

%C Similar to Hofstadter's Q-sequence A005185 but with different starting values.

%C Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.

%C a(n) exists for n <= 3*10^7.

%H Nathan Fox, <a href="/A278058/b278058.txt">Table of n, a(n) for n = 1..10000</a>

%H Nathan Fox, <a href="https://vimeo.com/191094180">Hofstadter-like Sequences over Nonstandard Integers</a>, Talk given at the Rutgers Experimental Mathematics Seminar, November 10 2016.

%t a[n_] := a[n] = If[0 < n < 7, n, a[n-a[n-1]] + a[n-a[n-2]]];

%t Array[a, 100] (* _Paolo Xausa_, May 29 2024 *)

%Y Cf. A005185, A278056, A278057, A278059, A278060, A278061, A278062, A278063, A278064, A278065.

%K nonn

%O 1,2

%A _Nathan Fox_, Nov 10 2016