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 A242021 #8 Aug 12 2014 03:28:36
%S A242021 7,2,7,4,5,0,9,1,3,2,4,0,0,2,2,8,1,4,3,2,6,6,1,7,2,3,5,5,6,4,5,2,0,4,
%T A242021 5,2,5,9,0,1,7,1,0,3,5,2,0,2,1,2,7,7,5,3,0,7,1,5,6,6,8,3,9,8,7,1,8,4,
%U A242021 1,5,0,8,8,2,8,1,4,5,2,4,2,4,7,5,3,2,9,3,1,6,3,1,0,9,1,0,3,1,6,4
%N A242021 Decimal expansion of the asymptotic growth rate of the number of odd coefficients in Pascal trinomial triangle mod 2.
%H A242021 Steven Finch, Pascal Sebah and Zai-Qiao Bai, <a href="http://arXiv.org/abs/0802.2654">Odd Entries in Pascal's Trinomial Triangle</a> (arXiv:0802.2654) p. 10.
%F A242021 log(abs(mu))/log(2) - 1, where mu is the root of x^4 - 3*x^3 - 2*x^2 + 2*x + 4 with maximum modulus.
%e A242021 0.727450913240022814326617235564520452590171035202127753...
%t A242021 mu = Sort[Table[Root[x^4 - 3*x^3 - 2*x^2 + 2*x + 4, x, n], {n, 1, 4}], N[Abs[#1]] < N[Abs[#2]]&] // Last; RealDigits[Log[Abs[mu]]/Log[2] - 1, 10, 100] // First
%K A242021 nonn,cons,easy
%O A242021 0,1
%A A242021 _Jean-François Alcover_, Aug 11 2014