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Relative of Hofstadter Q-sequence: a(1) = 37, a(2) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)).
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%I #8 May 30 2024 16:58:52

%S 37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,2,37,

%T 2,37,2,37,2,37,2,37,2,37,39,2,76,2,76,2,76,2,76,2,76,2,76,2,76,2,76,

%U 2,76,2,76,2,76,2,76,2,76,2,76,2,76,2,76,2,76,2,76,2,76,39

%N Relative of Hofstadter Q-sequence: a(1) = 37, a(2) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)).

%C In calculating terms of this sequence, use the convention that a(n)=0 for n<=0.

%C This sequence has exactly 3850 terms, since a(3850)=0 and computing a(3851) would refer to itself.

%C Superficially, this sequence behaves similarly to A278066. But, that sequence is infinite, but this sequence dies.

%H Nathan Fox, <a href="/A278067/b278067.txt">Table of n, a(n) for n = 1..3850</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[1] = 37; a[2] = 2; a[n_] := a[n] = If[n < 1, 0, a[n-a[n-1]] + a[n-a[n-2]]];

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

%Y Cf. A005185, A278066, A278068.

%K nonn,fini,full

%O 1,1

%A _Nathan Fox_, Nov 13 2016