OFFSET
1,2
COMMENTS
Conjectured to be infinite.
REFERENCES
D. R. Hofstadter, Curious patterns and non-patterns in a family of meta-Fibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014.
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 1..20000
D. R. Hofstadter, Curious patterns and non-patterns in a family of meta-Fibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014; Part 1, Part 2.
D. R. Hofstadter, Plot of first 100000 terms
MAPLE
# Q(r, s) with initial values 1, 2, 3, 4, ...
r:=2; s:=4;
a:=proc(n) option remember; global r, s;
if n <= s then n
else
if (a(n-r) <= n) and (a(n-s) <= n) then
a(n-a(n-r))+a(n-a(n-s));
else lprint("died with n =", n); return (-1);
fi;
fi; end;
[seq(a(n), n=1..100)];
PROG
(Magma) I:=[1, 2, 3, 4]; [n le 4 select I[n] else Self(n-Self(n-2))+Self(n-Self(n-4)): n in [1..100]]; // Vincenzo Librandi, Apr 16 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 15 2014, Apr 17 2014
STATUS
approved