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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103228 Real part of the sum of divisors function sigma(n) generalized for Gaussian integers. 18

%I

%S 1,2,4,-4,4,8,8,-8,13,-16,12,-16,6,16,16,16,6,26,20,-56,32,24,24,-32,

%T -36,-42,40,-32,8,-64,32,32,48,-54,32,-52,8,40,24,24,10,64,44,-48,52,

%U 48,48,64,57,-165,24,-114,10,80,48,-64,80,-92,60,-224,12,64,104,-64,-120,96,68,-134,96,-128,72,-104,12,-116,-144,-80,96

%N Real part of the sum of divisors function sigma(n) generalized for Gaussian integers.

%C See A103229 for the imaginary part and A103230 for the norm.

%C See A102506 for a complete description. Note that sigma(n) is real iff n is in A004614.

%H Amiram Eldar, <a href="/A103228/b103228.txt">Table of n, a(n) for n = 1..10000</a>

%t Re[Table[DivisorSigma[1, n, GaussianIntegers -> True], {n, 100}]]

%Y Cf. A004614, A102506, A103229, A103230.

%K sign

%O 1,2

%A _T. D. Noe_, Jan 26 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | 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 27 22:01 EDT 2022. Contains 357063 sequences. (Running on oeis4.)