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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A062731 Sum of divisors of 2*n. 18
3, 7, 12, 15, 18, 28, 24, 31, 39, 42, 36, 60, 42, 56, 72, 63, 54, 91, 60, 90, 96, 84, 72, 124, 93, 98, 120, 120, 90, 168, 96, 127, 144, 126, 144, 195, 114, 140, 168, 186, 126, 224, 132, 180, 234, 168, 144, 252, 171, 217, 216, 210, 162, 280, 216, 248, 240, 210 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 1..20000 [First 1000 terms from Harry J. Smith]

FORMULA

a(n) = A000203(2*n). - R. J. Mathar, Apr 06 2011

MATHEMATICA

lst={}; Do[AppendTo[lst, DivisorSigma[1, n]], {n, 2, 6!, 2}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 20 2008 *)

PROG

(PARI) vector(66, n, sigma(2*n, 1))

(PARI) for (n=1, 1000, write("b062731.txt", n, " ", sigma(2*n)) ) \\ Harry J. Smith, Aug 09 2009

(MuPAD) numlib::sigma(2*n)$ n=0..81 // Zerinvary Lajos, May 13 2008

(MAGMA) [SumOfDivisors(2*n): n in [1..70]]; // Vincenzo Librandi, Oct 31 2014

CROSSREFS

Cf. A000203, A008438, A074400.

Sequence in context: A310224 A310225 A310226 * A236375 A310227 A310228

Adjacent sequences:  A062728 A062729 A062730 * A062732 A062733 A062734

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Jul 11 2001

EXTENSIONS

Zero removed and offset corrected by Omar E. Pol, Jul 17 2009

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 October 15 15:14 EDT 2019. Contains 328030 sequences. (Running on oeis4.)