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 A085119 #24 May 30 2025 15:03:46 %S A085119 1,1,1,1,1,1,5,2,1,1,1,9,13,13,13,13,13,2,13,13,17,13,13,5,13,13,13, %T A085119 22,13,5,29,1,13,13,13,29,13,13,13,7,13,1,17,13,29,1,13,1,33,49,13,20, %U A085119 31,11,13,11,3,19,13,19,61,13,61,13,61,27,49,10,13,40,13,34,37 %N A085119 a(n) = number at which the standard Ackermann function mod n stabilizes, or -1 if it does not stabilize. %C A085119 a(1969) = -1, but otherwise a(n) is positive for all n >= 2 and < 8000000. %C A085119 [Needs program(s). - _N. J. A. Sloane_, May 25 2025] %H A085119 J. Froemke and J. W. Grossman, <a href="http://www.jstor.org/stable/2323780">A mod-n Ackermann function, or what's so special about 1969?</a>, Amer. Math. Monthly, 100 (1993), 180-183. %H A085119 Mark Rickert, <a href="/A352196/a352196-8M.gz">The first 8 million terms a(n)</a> [a gzipped file], March 2022. %H A085119 Stan Wagon, <a href="/A352196/a352196.pdf">Problem of the Week POW #1340: Modular Ackermann</a>, March 2022. %H A085119 Stan Wagon, <a href="/A352196/a352196_1.pdf">Problem of the Week POW #1340: Solution</a>, March 2022. %Y A085119 Cf. A352196, A383460. %K A085119 nonn %O A085119 2,7 %A A085119 _Jerrold Grossman_, Apr 25 2004 %E A085119 Revised by _N. J. A. Sloane_, May 25 2025