cp's OEIS Frontend

A283882 Relative of Hofstadter Q-sequence: a(n) = max(0, n+67) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 0.

%I A283882 #4 Mar 19 2017 19:24:15
%S A283882 3,68,69,5,70,6,7,71,73,10,8,73,77,12,74,14,79,11,78,82,16,13,17,15,
%T A283882 81,20,20,142,73,24,32,138,3,32,207,5,138,3,5,345,5,138,3,5,483,5,138,
%U A283882 3,5,621,5,138,3,5,759,5,138,3,5,897,5,138,3,5,1035,5,138,3,5,1173,5,138,5,8,1311
%N A283882 Relative of Hofstadter Q-sequence: a(n) = max(0, n+67) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 0.
%C A283882 Sequences like this are more naturally considered with the first nonzero term in position 1. But this sequence would then match A000027 for its first 67 terms.
%H A283882 Nathan Fox, <a href="/A283882/b283882.txt">Table of n, a(n) for n = 1..10000</a>
%F A283882 If the index is between 35 and 72 (inclusive), then a(5n) = 138n-759, a(5n+1) = 5, a(5n+2) = 138, a(5n+3) = 3, a(5n+4) = 5.
%F A283882 If the index is between 78 and 1245 (inclusive), then a(5n) = 1311, a(5n+1) = 3, a(5n+2) = 5, a(5n+3) = 1311n-17181, a(5n+4) = 5.
%F A283882 If the index is between 1251 and 309192 (inclusive), then a(5n) = 5, a(5n+1) = 19047817435n-1178393232110703, a(5n+2) = 5, a(5n+3) = 19047817435, a(5n+4) = 3.
%F A283882 If the index is between 309336 and 19047817368 (inclusive), then a(5n) = 5, a(5n+1) = 309258n-76697295, a(5n+2) = 5, a(5n+3) = 309258, a(5n+4) = 3.
%F A283882 If the index is at least 19047817371, then a(5n) = 5*A272611(n-3809563474), a(5n+1) = 5*A272611(n-3809563473), a(5n+2) = 5*A272612(n-3809563473), a(5n+3) = 19047817435*A272613(n-3809563473), a(5n+4) = 4. This pattern lasts as long as A272611 exists (which is conjectured to be forever).
%p A283882 A283882:=proc(n) option remember: if n <= 0 then max(0, n+67): else A283882(n-A283882(n-1)) + A283882(n-A283882(n-2)): fi: end:
%Y A283882 Cf. A005185, A272610, A272611, A272612, A272613, A274058, A283883.
%K A283882 nonn
%O A283882 1,1
%A A283882 _Nathan Fox_, Mar 19 2017