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 A007780 #20 Jan 25 2018 14:09:38 %S A007780 1,2,3,6,9,11,18,20,27,30,54,81,162,168,243,486,729,1458,2187,4374, %T A007780 6561,13122,19683,39366,59049,118098,177147,354294,531441,1062882, %U A007780 1594323,3188646,4782969,9565938,14348907,28697814,43046721,86093442 %N A007780 Losing initial configurations in 2-hole Tchuka Ruma. %C A007780 The 2-hole Tchuka Ruma game cannot be won for the initial seeds 3^i (i>=1) or 2*3^i (i>=0). Though a sufficient condition, this is not necessary, as can be seen from the terms a(6)=11, a(8)=20, a(10)=30 and a(14)=168. - Pab Ter (pabrlos2(AT)yahoo.com), Nov 08 2005 %C A007780 If any further sporadic term exists, then it exceeds 6973568802. - _Sean A. Irvine_, Jan 25 2018 %H A007780 Sean A. Irvine, <a href="/A007780/b007780.txt">Table of n, a(n) for n = 1..46</a> %H A007780 Paul J. Campbell, and Darrah P. Chavey, <a href="https://www.beloit.edu/computerscience/assets/tchuka.pdf">Tchuka Ruma Solitaire</a>, The UMAP Journal 16(4) (1995), 343-365. %F A007780 Conjectures from _Colin Barker_, Jan 25 2018: (Start) %F A007780 G.f.: x*(1 + 2*x - 7*x^5 - 9*x^6 - 13*x^7 - 27*x^8 - 30*x^9 - 27*x^10 - 9*x^11 - 75*x^13 - 243*x^14 - 18*x^15) / (1 - 3*x^2). %F A007780 a(n) = 3*a(n-2) for n>2. %F A007780 (End) %K A007780 nonn %O A007780 1,2 %A A007780 _Darrah Chavey_ %E A007780 More terms from Pab Ter (pabrlos2(AT)yahoo.com), Nov 08 2005 %E A007780 More terms from _Sean A. Irvine_, Jan 25 2018