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 A299627 #15 Feb 16 2025 08:33:53 %S A299627 8,1,6,4,6,8,2,0,8,9,7,1,2,8,4,0,5,9,1,0,9,3,8,8,7,3,7,1,1,5,6,5,4,2, %T A299627 2,8,7,6,6,4,4,9,4,1,9,9,6,0,4,6,7,3,7,3,4,7,7,1,0,8,1,6,3,2,1,5,6,7, %U A299627 1,7,8,1,2,3,1,1,7,7,9,2,3,3,8,4,3,3 %N A299627 Decimal expansion of e^(2*W(3)) = 9/(W(3))^2, where W is the Lambert W function (or PowerLog); see Comments. %C A299627 The Lambert W function satisfies the functional equation e^(W(x) + W(y)) = x*y/(W(x)*W(y)) for x and y greater than -1/e, so that e^(2*W(3)) = 9/(W(3))^2. See A299613 for a guide to related constants. %H A299627 G. C. Greubel, <a href="/A299627/b299627.txt">Table of n, a(n) for n = 1..10000</a> %H A299627 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LambertW-Function.html">Lambert W-Function</a> %e A299627 e^(2*W(3)) = 8.1646820897128405910938873711... %t A299627 w[x_] := ProductLog[x]; x = 3; y = 3; %t A299627 N[E^(w[x] + w[y]), 130] (* A299627 *) %t A299627 RealDigits[(3/LambertW[3])^2, 10, 100][[1]] (* _G. C. Greubel_, Mar 06 2018 *) %o A299627 (PARI) (3/lambertw(3))^2 \\ _G. C. Greubel_, Mar 06 2018 %Y A299627 Cf. A299613, A299626. %K A299627 nonn,cons,easy %O A299627 1,1 %A A299627 _Clark Kimberling_, Mar 03 2018