login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 


Decimal expansion of x > 0 satisfying 2*x + 1 = exp(x).
2

%I #16 Nov 10 2017 09:54:47

%S 1,2,5,6,4,3,1,2,0,8,6,2,6,1,6,9,6,7,6,9,8,2,7,3,7,6,1,6,6,0,9,2,1,6,

%T 3,2,6,9,1,6,4,1,6,8,3,1,7,0,1,3,2,3,7,1,1,1,2,5,8,9,4,7,2,7,0,4,8,3,

%U 0,0,4,7,8,5,4,1,0,5,1,9,0,3,5,3,3,6,6,4,7,5,0,9,4,7,2,5,0,8,4

%N Decimal expansion of x > 0 satisfying 2*x + 1 = exp(x).

%C See A202320 for a guide to related sequences. The Mathematica program includes a graph.

%H G. C. Greubel, <a href="/A202343/b202343.txt">Table of n, a(n) for n = 1..10000</a>

%e x = 1.25643120862616967698273761660921...

%t u = 2; v = 1;

%t f[x_] := u*x + v; g[x_] := E^x

%t Plot[{f[x], g[x]}, {x, -3, 2}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, 1.2, 1.3}, WorkingPrecision -> 110]

%t RealDigits[r] (* A202343 *)

%t RealDigits[-1/2 - ProductLog[-1, -1/(2*Sqrt[E])], 10, 99] // First (* _Jean-François Alcover_, Feb 27 2013 *)

%o (PARI) solve(x=1, 2, 2*x+1-exp(x)) \\ _Michel Marcus_, Nov 09 2017

%Y Cf. A202320.

%K nonn,cons

%O 1,2

%A _Clark Kimberling_, Dec 17 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 21 04:06 EDT 2024. Contains 376079 sequences. (Running on oeis4.)