This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A240816 #21 Jul 20 2021 03:11:43 %S A240816 7,0,15,165,55,14,0,0,11,12,61,38,12,13,14,2355,31,14,14,15,16,283,64, %T A240816 45,15,16,18,19,1337,369,32,16,18,19,20 %N A240816 Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = index of first nonexisting term of the meta-Fibonacci sequence {f(1) = ... = f(n) = 1; f(i)=f(i-f(i-k))+f(i-f(i-n))} if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite. %C A240816 The zero entries (except T(4,1)) are only conjectural. %C A240816 Apart from the zero entries, equals A240813 + 1. %H A240816 B. Balamohan, A. Kuznetsov and S. Tanny, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL10/Tanny/tanny3.html">On the behavior of a variant of Hofstadter's Q-sequence</a>, J. Integer Sequences, Vol. 10 (2007), #07.7.1. %H A240816 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; <a href="https://vimeo.com/91708646">Part 1</a>, <a href="https://vimeo.com/91710600">Part 2</a>. %H A240816 <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a> %e A240816 Triangle begins: %e A240816 7; %e A240816 0, 15; %e A240816 165, 55, 14; %e A240816 0, 0, 11, 12; %e A240816 61, 38, 12, 13, 14; %e A240816 2355, 31, 14, 14, 15, 16; %e A240816 283, 64, 45, 15, 16, 18, 19; %e A240816 1337, 369, 32, 16, 18, 19, 20, ?; %e A240816 ... %Y A240816 Diagonals give A240810, A240814, A240815. %Y A240816 See A240813 for another version. %K A240816 nonn,tabl,more %O A240816 1,1 %A A240816 _N. J. A. Sloane_, Apr 15 2014