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 A242743 #34 Sep 08 2022 08:46:08 %S A242743 9,2,9,6,9,5,3,9,8,3,4,1,6,1,0,2,1,4,9,8,5,3,8,4,9,7,3,6,6,5,8,7,8,1, %T A242743 2,1,7,6,5,8,8,2,3,7,5,1,5,1,8,0,2,1,6,7,5,8,2,3,4,3,1,4,2,9,7,0,1,9, %U A242743 2,0,8,4,7,4,5,7,2,5,0,8,1,2,5,6,1,8,5,3,1,2,1,0,4,4,7,7,4,6,1,5,8,8,9,4,6 %N A242743 Decimal expansion of an Ising constant related to the random coloring problem. %C A242743 In Ising model on the 2D square lattice, the negated ratio of free energy per node to the temperature at the critical point. - _Andrey Zabolotskiy_, Sep 12 2017 %D A242743 Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.22 Lenz-Ising constants, p. 399. %H A242743 G. C. Greubel, <a href="/A242743/b242743.txt">Table of n, a(n) for n = 0..10000</a> %H A242743 Lars Onsager, <a href="https://doi.org/10.1103/PhysRev.65.117">Crystal Statistics. I. A Two-Dimensional Model with an Order-Disorder Transition</a>, Phys. Rev. 65, 117 (1944) [see eq. (121)]. %F A242743 log(2)/2 + 2*G/Pi = log(2)/2 + A218387/2, where G is Catalan's constant. %e A242743 0.929695398341610214985384973665878... %t A242743 RealDigits[Log[2]/2 + 2*Catalan/Pi, 10, 105] // First %o A242743 (PARI) default(realprecision, 100); log(2)/2 + 2*Catalan/Pi \\ _G. C. Greubel_, Aug 25 2018 %o A242743 (Magma) SetDefaultRealField(RealField(100)); R:=RealField(); Log(2)/2 + 2*Catalan(R)/Pi(R); // _G. C. Greubel_, Aug 25 2018 %Y A242743 Cf. A002898, A006752, A218387, A245592. %K A242743 nonn,cons %O A242743 0,1 %A A242743 _Jean-François Alcover_, Jun 02 2014