A240810 a(n) = index of first nonexisting term of the meta-Fibonacci sequence {f(1) = ... = f(n) = 1; f(k)=f(k-f(k-1))+f(k-f(k-n))} if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite.

7, 0, 165, 0, 61, 2355, 283, 1337, 101, 1255, 367, 420, 499, 484, 779, 1205, 293, 374, 846, 839, 1119, 2121, 816, 2617, 687, 1196, 746, 1113, 2133, 1589, 755, 1228, 1280, 1662, 717, 2276, 785, 2342, 1875, 1464, 1123, 2801, 1351, 1614, 2280, 1558, 1533

Offset: 1

Author

N. J. A. Sloane, Apr 15 2014

Keywords

• nonn

Comments

a(2)=0 is only a conjecture (see A005185), whereas a(4)=0 is a theorem of Balamohan et al. (2007).

Except for the two zero entries, this is equal to A134680(n)+1. See that entry for further information.

Links

• B. Balamohan, A. Kuznetsov and S. Tanny, On the behavior of a variant of Hofstadter's Q-sequence, J. Integer Sequences, Vol. 10 (2007), #07.7.1.
• 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.
• Index entries for Hofstadter-type sequences

Crossrefs

See A134680 for another version.

A diagonal of the triangle in A240816.