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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A075708 Sum of the divisors of 2^n - 1. 1
1, 4, 8, 24, 32, 104, 128, 432, 592, 1536, 2160, 8736, 8192, 22528, 38912, 111456, 131072, 473600, 524288, 1999872, 2466048, 5909760, 8567136, 38054016, 34713728, 89522176, 155493536, 462274560, 539922240, 2015330304, 2147483648 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a(n) = sigma(2^n - 1).

MATHEMATICA

Table[DivisorSigma[1, 2^n - 1], {n, 1, 40}]

CROSSREFS

Sequence in context: A026596 A181688 A083504 * A066617 A024589 A062015

Adjacent sequences:  A075705 A075706 A075707 * A075709 A075710 A075711

KEYWORD

easy,nonn

AUTHOR

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Oct 03 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 08:13 EST 2012. Contains 205893 sequences.