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 A019808 #13 Sep 08 2022 08:44:44 %S A019808 1,1,1,0,3,0,6,6,5,7,9,0,3,3,9,2,4,7,7,7,9,2,1,6,0,0,2,9,6,0,4,0,0,0, %T A019808 4,1,7,3,2,3,9,2,2,0,4,7,2,3,2,1,8,4,9,6,3,3,3,7,1,8,8,7,8,4,6,5,5,2, %U A019808 4,2,8,8,0,6,7,2,6,9,3,9,7,5,9,5,3,6,3,3,3,2,9,4,2,6,4,1,7,9,7 %N A019808 Decimal expansion of sqrt(2*e)/21. %H A019808 Ivan Panchenko, <a href="/A019808/b019808.txt">Table of n, a(n) for n = 0..1000</a> %e A019808 0.1110306657903392477792160029604000417323922047232184963... %t A019808 RealDigits[Sqrt[2*E]/21, 10, 100][[1]] (* _G. C. Greubel_, Sep 08 2018 *) %o A019808 (PARI) default(realprecision, 100); sqrt(2*exp(1))/21 \\ _G. C. Greubel_, Sep 08 2018 %o A019808 (Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Sqrt(2*Exp(1))/21; // _G. C. Greubel_, Sep 08 2018 %Y A019808 Cf. A019798 (sqrt(2*e)). %K A019808 nonn,cons %O A019808 0,5 %A A019808 _N. J. A. Sloane_