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 A246728 #17 Feb 11 2025 08:49:07 %S A246728 5,3,3,2,9,6,4,1,6,6,6,0,3,1,2,8,6,7,6,0,0,8,3,8,0,9,9,3,1,8,0,9,3,5, %T A246728 9,4,0,9,4,6,7,6,0,6,3,8,8,5,2,8,0,9,1,6,9,3,0,2,2,1,3,5,8,4,7,5,7,2, %U A246728 8,7,0,6,4,9,2,2,3,4,1,4,8,6,5,7,1,3,5,2,0,7,2,2,5,1,5,9,1,3,2,0,9 %N A246728 Decimal expansion of r_7, the 7th smallest radius < 1 for which a compact packing of the plane exists, with disks of radius 1 and r_7. %H A246728 Steven R. Finch, <a href="http://arxiv.org/abs/2001.00578">Errata and Addenda to Mathematical Constants</a>, p. 62. %H A246728 <a href="/index/Al#algebraic_03">Index entries for algebraic numbers, degree 3</a>. %F A246728 1st root of 8x^3 + 3x^2 - 2x - 1. %e A246728 0.53329641666031286760083809931809359409467606388528091693... %t A246728 RealDigits[Root[8x^3 + 3x^2 - 2x - 1, x, 1], 10, 101] // First %o A246728 (PARI) polrootsreal(8*x^3+3*x^2-2*x-1)[1] \\ _Charles R Greathouse IV_, Feb 11 2025 %Y A246728 Cf. A246723 (r_1), A246724 (r_2), A246725 (r_3), A246726 (r_4), A246727 (r_5), A002193 (r_6 = sqrt(2)-1), A246729 (r_8), A246730 (r_9). %K A246728 nonn,cons,easy %O A246728 0,1 %A A246728 _Jean-François Alcover_, Sep 02 2014