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 A066400 #47 May 08 2025 08:54:27 %S A066400 1,3,3,1,3,3,3,4,1,4,3,3,3,5,4,1,3,3,3,3,3,3,3,3,1,4,5,4,3,3,3,3,5,4, %T A066400 4,1,3,3,3,3,3,3,3,3,3,3,3,3,1,3,5,6,3,4,5,3,3,4,3,5,3,4,5,1,6,5,3,3, %U A066400 3,5,3,5,3,3,6,3,4,5,3,3,1,3,3,4,5,3,3,3,3,6,6,5,3,3,5,3,3,6,7,1,3,6,3,5,4 %N A066400 Smallest values of t arising in R. L. Graham's sequence (A006255). %C A066400 Length of n-th row in table A245499. - _Reinhard Zumkeller_, Jul 25 2014 %C A066400 Indices of records are 1, 2, 8, 14, 52, 99, 589, 594, 595... (A277649) - _Peter Kagey_, Oct 24 2016 %C A066400 It is conjectured that 2 never appears in this sequence. a(n) = 2 if and only if A006255(n) = A072905(n). - _Peter Kagey_, Oct 25 2016 %C A066400 a(n) is three most of the time, then 5, then 6, then 4 for the first 1000 and the first 10000 terms. At n = 72, 78 and 85, a(n) is 4 or 5 and 4 and 5 occurred equally often so far. At 299, 301, 312, 322 and 403, a(n) is 4 or 6 and 4 and 6 occurred equally often so far. This doesn't happen for the first 10000 terms for 5 and 6. - _David A. Corneth_, Oct 25 2016 %D A066400 R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 147. %H A066400 David A. Corneth, <a href="/A066400/b066400.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Reinhard Zumkeller and Peter Kagey) %H A066400 R. L. Graham, <a href="http://www.jstor.org/stable/2689569">Bijection between integers and composites</a>, Problem 1242, Math. Mag., 60 (1987), p. 180. %e A066400 a(2) = 3 because the best such sequence is 2,3,6 which has three terms. %o A066400 (Haskell) %o A066400 a066400 = length . a245499_row -- _Reinhard Zumkeller_, Jul 25 2014 %Y A066400 Cf. A006255, A066401, A072905. %Y A066400 Cf. A245499, A277649. %K A066400 nonn %O A066400 1,2 %A A066400 _N. J. A. Sloane_, Dec 25 2001 %E A066400 More terms from _John W. Layman_, Jul 14 2003 %E A066400 More terms from _Joshua Zucker_, May 18 2006