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 A240825 #18 Jul 19 2021 19:26:31
%S A240825 7,0,14,163,30,21,0,0,72,28,57,30,35,36,29,2350,25,0,29,55,42,277,51,
%T A240825 47,45,35,56,41,1301,0,35,0,38,69,90
%N A240825 Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = index of first nonexisting term of the meta-Fibonacci sequence {f(i)=i for i <= n; thereafter 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 A240825 The zero entries are only conjectural. More precisely, Hofstadter conjectures that T(n,k) = 0 (i.e., the sequence is immortal) iff n = 2k or n = 4k.
%C A240825 Apart from the zero entries, equals A240821 + 1.
%D A240825 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.
%H A240825 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 A240825 <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a>
%e A240825 Triangle begins:
%e A240825 7;
%e A240825 0, 14;
%e A240825 163, 30, 21;
%e A240825 0, 0, 72, 28;
%e A240825 57, 30, 35, 36, 29;
%e A240825 2350, 25, 0, 29, 55, 42;
%e A240825 277, 51, 47, 45, 35, 56, 41;
%e A240825 1301, 0, 35, 0, 38, 69, 90, ...
%e A240825 ...
%Y A240825 Diagonals give A240822, A240823, A240824.
%Y A240825 See A240821 for another version.
%K A240825 nonn,tabl,more
%O A240825 1,1
%A A240825 _N. J. A. Sloane_, Apr 15 2014