login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A257535 Decimal expansion of the imaginary part of -E_1(i), i being the imaginary unit. 3
6, 2, 4, 7, 1, 3, 2, 5, 6, 4, 2, 7, 7, 1, 3, 6, 0, 4, 2, 8, 9, 9, 6, 8, 3, 7, 7, 8, 1, 6, 5, 7, 1, 7, 8, 4, 2, 8, 6, 2, 4, 6, 7, 4, 4, 9, 4, 9, 4, 4, 1, 1, 2, 0, 0, 1, 6, 0, 1, 7, 5, 2, 2, 5, 8, 7, 2, 2, 1, 1, 6, 6, 6, 0, 2, 3, 0, 6, 5, 8, 1, 2, 2, 5, 3, 1, 5, 2, 7, 9, 5, 8, 9, 3, 1, 7, 8, 2, 2, 7, 7, 6, 0, 5, 0 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

E_1(z) = Integral_{t>=1}(exp(-t*z)/t) is the exponential integral.

LINKS

Stanislav Sykora, Table of n, a(n) for n = 0..2000

Wikipedia, Exponential integral

FORMULA

Equals imag(E_1(-i)) and (Pi/2) - A099281.

EXAMPLE

0.6247132564277136042899683778165717842862467449494411200160175...

PROG

(PARI) a = imag(-eint1(I))

CROSSREFS

Cf. A099281, A099282, A099285.

Sequence in context: A061496 A125115 A202244 * A020831 A156590 A135617

Adjacent sequences:  A257532 A257533 A257534 * A257536 A257537 A257538

KEYWORD

nonn,cons

AUTHOR

Stanislav Sykora, Apr 28 2015

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified July 25 20:28 EDT 2017. Contains 289797 sequences.