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 A245720 #8 May 18 2025 03:42:06 %S A245720 1,1,1,8,4,4,2,7,5,2,8,4,5,4,9,6,9,5,6,7,5,3,4,4,3,3,6,0,5,1,6,1,1,1, %T A245720 8,0,3,8,2,7,5,1,1,9,4,4,1,3,2,1,2,2,0,1,4,5,8,2,8,0,0,2,3,3,5,4,6,7, %U A245720 2,7,3,4,0,2,4,6,6,3,2,4,6,3,0,1,5,2,4,6,6,0,9,7,2,3,1,1,5,9,5,2,2,8,4,7 %N A245720 Decimal expansion of the mean cluster density for bond percolation on the triangular lattice. %D A245720 Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.18 Percolation Cluster Density Constants, p. 373. %F A245720 35/4 - 3/p_c, where p_c = A130880 = 2*sin(Pi/18) is the critical probability. %e A245720 0.11184427528454969567534433605161118038275119441321220145828... %t A245720 RealDigits[35/4 - 3/(2*Sin[Pi/18]), 10, 104] // First %o A245720 (PARI) 35/4 - 3/(2*sin(Pi/18)) \\ _Stefano Spezia_, May 17 2025 %Y A245720 Cf. A130880. %K A245720 nonn,cons %O A245720 0,4 %A A245720 _Jean-François Alcover_, Jul 30 2014