# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a240829 Showing 1-1 of 1 %I A240829 #13 Apr 16 2014 16:59:58 %S A240829 -1,0,1,3,2,4,4,7,4,7,7,9,8,9,11,10,10,13,15,13,13,13,18,15,18,18,18, %T A240829 18,18,23,23,20,19,23,28,27,23,25,27,28,25,26,28,30,31,32,33,33,32,34, %U A240829 33,38,36,39,34,36,36,39,39,39,39,44,46,46,43,46,46,44,44,49,49,49,46,51,48,51,51,54,54,54,54,54 %N A240829 a(1)=-1, a(2)=0, a(3)=1; thereafter a(n) = Sum(a(n-i-s-a(n-i-1)),i=0..k-1) where s=0, k=3. %D A240829 Callaghan, Joseph, John J. Chew III, and Stephen M. Tanny. "On the behavior of a family of meta-Fibonacci sequences." SIAM Journal on Discrete Mathematics 18.4 (2005): 794-824. See Fig. 1.7. %H A240829 N. J. A. Sloane, Table of n, a(n) for n = 1..20000 %H A240829 Index entries for Hofstadter-type sequences %p A240829 #T_s,k(n) from Callaghan et al. Eq. (1.6). %p A240829 s:=0; k:=3; %p A240829 a:=proc(n) option remember; global s,k; %p A240829 if n <= 3 then n-2 %p A240829 else %p A240829 add(a(n-i-s-a(n-i-1)),i=0..k-1); %p A240829 fi; end; %p A240829 t1:=[seq(a(n),n=1..100)]; %Y A240829 Same recurrence as A240828, A120503 and A046702. %K A240829 sign,hear %O A240829 1,4 %A A240829 _N. J. A. Sloane_, Apr 16 2014 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE