login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A224842 Decimal expansion of log((1+e)/2). 0
6, 2, 0, 1, 1, 4, 5, 0, 6, 9, 5, 8, 2, 7, 7, 5, 2, 4, 6, 3, 1, 7, 6, 3, 3, 7, 3, 5, 0, 9, 6, 7, 9, 0, 7, 3, 8, 3, 9, 7, 7, 9, 9, 5, 1, 3, 1, 0, 0, 9, 3, 1, 2, 0, 5, 9, 8, 3, 8, 3, 5, 0, 5, 3, 4, 3, 8, 0, 1, 2, 7, 9, 5, 3, 9, 4, 9, 2, 5, 0, 5, 3, 3, 0, 3, 3, 7, 0, 7, 9, 2, 8, 0, 8, 7, 3, 7, 0, 3, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Positive matrices do not always behave like positive numbers: for instance 0 <= A <= B does not imply e^A <= e^B [e^A stands here for matrix exponential of A, and 0 <= A <= B means that A and B-A are positive matrices, a positive matrix being a matrix which has nonnegative entries]. The counterexample given by Paul Halmos is A = e^{{1/2, 1/2}, {1/2, 1/2}} = {{(1+e)/2, (e-1)/2}, {(e-1)/2, (1+e)/2}} and B = {{e^x, 0}, {0, e^y}}, with x < log((1+e)/2).

REFERENCES

Paul Halmos, "Problems for Mathematicians, Young and Old", Dolciani Mathematical Expositions, 1991, Solution to problem 9Q (Exponential inequality) p. 273.

LINKS

Table of n, a(n) for n=0..99.

FORMULA

Equals Integral_{x=0..1} 1/(exp(-x) + 1) dx. - Amiram Eldar, Aug 16 2020

EXAMPLE

0.620114506958277524631763373509679073839779951310093120598383505343801279539...

MATHEMATICA

RealDigits[Log[(1 + E)/2], 10, 100][[1]]

CROSSREFS

Sequence in context: A224476 A123147 A119831 * A318138 A130143 A195486

Adjacent sequences:  A224839 A224840 A224841 * A224843 A224844 A224845

KEYWORD

nonn,cons

AUTHOR

Jean-Fran├žois Alcover, Jul 22 2013

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 24 11:26 EDT 2020. Contains 337318 sequences. (Running on oeis4.)