A278063 - OEIS

%I #17 May 30 2024 06:54:04

%S 1,2,3,4,5,6,7,8,9,10,11,3,12,13,5,14,6,7,15,17,10,8,17,21,12,18,14,

%T 23,11,22,26,16,13,17,15,25,11,26,35,18,23,36,24,25,27,25,25,34,26,35,

%U 26,24,25,33,30,35,22,42,17,31,47,31,30,30

%N Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 11; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 11.

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

%C This sequence has exactly 199 terms, since a(199)=206 and computing a(200) would refer to a(-6).

%H Nathan Fox, <a href="/A278063/b278063.txt">Table of n, a(n) for n = 1..199</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 < 12, n, a[n-a[n-1]] + a[n-a[n-2]]];

%t Array[a, 100] (* _Paolo Xausa_, May 30 2024 *)

%o (Magma) [n le 11 select n else Self(n-Self(n-1))+Self(n-Self(n-2)): n in [1..70]]; // _Bruno Berselli_, Nov 15 2016

%Y Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278064, A278065.

%K nonn,fini,full

%O 1,2

%A _Nathan Fox_, Nov 10 2016