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A283897 Relative of Hofstadter Q-sequence: a(-90) = 91, a(-89) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)).

%I A283897 #4 Mar 19 2017 19:26:14
%S A283897 93,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,
%T A283897 2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,184,2,
%U A283897 184,2,184,2,184,2,184,2,184,2,184,2,184,2
%N A283897 Relative of Hofstadter Q-sequence: a(-90) = 91, a(-89) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)).
%C A283897 In calculating terms of this sequence, use the convention that a(n)=0 for n<=-91.
%C A283897 Sequences like this are more naturally considered with the first nonzero term in position 1. But this sequence would then begin with 91 terms consisting entirely of alternating 2 and 91.
%C A283897 This sequence has exactly 375 terms, since a(375)=0 and computing a(376) would refer to itself.
%H A283897 Nathan Fox, <a href="/A283897/b283897.txt">Table of n, a(n) for n = 1..375</a>
%p A283897 A283897:=proc(n) option remember: if n <= -91 then 0: elif n = -90 then 91: elif n = -89 then 2: else A283897(n-A283897(n-1)) + A283897(n-A283897(n-2)): fi: end:
%Y A283897 Cf. A005185, A278066, A278067, A278068, A283893, A283894, A283895, A283896.
%K A283897 nonn,fini,full
%O A283897 1,1
%A A283897 _Nathan Fox_, Mar 19 2017