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 A071074 #11 Jan 11 2017 19:52:14 %S A071074 0,1,2,3,4,5,6,7,3,2,8,9,7,6,5,4,3,2,8,9,4,5,12,13,9,8,2,3,4,5,15,14, %T A071074 3,2,8,9,7,6,5,4,3,2,8,9,13,12,15,14,9,8,2,3,4,5,16,17,10,11,8,9,14, %U A071074 15,5,4,3,2,16,17,13,12,15,14,9,8,2,3,4,5,6,7,3,2,8,9,14,15,5,4,3,2 %N A071074 Sprague-Grundy values for the game of Double Kayles (octal game .7777). %C A071074 Sequence is eventually periodic with period 24. The last exception is at n=141. - _Eric M. Schmidt_, Jan 11 2017 %D A071074 E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982, see p. 98. %D A071074 J. H. Conway, On Numbers and Games, Second Edition. A K Peters, Ltd, 2001, p. 129. %D A071074 Guy, R. K. and Smith, C. A. B.; The G-values of various games. Proc. Cambridge Philos. Soc. 52 (1956), 514-526. See page 521. %H A071074 Eric M. Schmidt, <a href="/A071074/b071074.txt">Table of n, a(n) for n = 0..200</a> %H A071074 Achim Flammenkamp, <a href="http://www.uni-bielefeld.de/~achim/octal_sparse.html">Octal games</a> %F A071074 Let b=A002186. Cases A, B: b(n)=0, 2, 5, 7. Cases C, D: b(n)=1, 3, 4, 6, 8. Cases A, C: n even. Cases B, D: n odd. Cases A, D: a(2n)=2*b(n), a(2n+1)=2*b(n)+1. Cases B, C: a(2n)=2*b(n)+1, a(2n+1)=2*b(n). %Y A071074 Cf. A002186. %K A071074 nonn %O A071074 0,3 %A A071074 _N. J. A. Sloane_, May 26 2002 %E A071074 Edited and extended by _Christian G. Bower_, Oct 22 2002