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 A299617 #9 Feb 16 2025 08:33:53 %S A299617 4,7,9,2,9,3,6,5,9,0,1,4,2,8,1,4,0,2,5,7,2,5,8,4,7,3,7,2,3,8,2,1,0,8, %T A299617 6,0,1,5,9,6,7,8,6,3,9,6,2,8,4,3,7,6,3,9,1,3,6,6,9,9,8,4,6,8,1,6,8,5, %U A299617 7,7,9,5,1,4,5,2,0,4,4,0,1,7,7,4,8,4 %N A299617 Decimal expansion of e^(W(1) + W(e)) = e/(W(1)*W(e)), where W is the Lambert W function (or PowerLog); see Comments. %C A299617 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^(W(1) + W(e)) = e/(W(1)*W(e)). See A299613 for a guide to related constants. %H A299617 G. C. Greubel, <a href="/A299617/b299617.txt">Table of n, a(n) for n = 1..10000</a> %H A299617 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LambertW-Function.html">Lambert W-Function</a> %e A299617 e^(W(1) + W(e)) = 4.7929365901428140257258473723821086015... %t A299617 w[x_] := ProductLog[x]; x = 1; y = E; %t A299617 N[E^(w[x] + w[y]), 130] (* A299617 *) %t A299617 RealDigits[E/(LambertW[1]*LambertW[E]), 10, 100][[1]] (* _G. C. Greubel_, Mar 03 2018 *) %o A299617 (PARI) exp(1)/(lambertw(1)*lambertw(exp(1))) \\ _G. C. Greubel_, Mar 03 2018 %Y A299617 Cf. A299613, A030178. %K A299617 nonn,cons,easy %O A299617 1,1 %A A299617 _Clark Kimberling_, Mar 01 2018