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!)
A067806 Numbers n such that sigma(n+1)+sigma(n)=3n. 3

%I

%S 10,34,136,169,2402,5329,21004,41164,54722,1060802,5026562,10800112,

%T 11108164,14366402,87026656,102944992,10499710072,107000850688,

%U 220200311872,924354816004

%N Numbers n such that sigma(n+1)+sigma(n)=3n.

%C a(21) > 10^13. - _Giovanni Resta_, Jul 11 2013

%t For[n=1, True, n++, If[DivisorSigma[1, n]+DivisorSigma[1, n+1]==3n, Print[n]]]

%Y Cf. A068077, A068078.

%K more,nonn

%O 1,1

%A _Benoit Cloitre_, Feb 07 2002

%E Edited by _Dean Hickerson_, Feb 16 2002

%E a(17) from _Donovan Johnson_, Jan 31 2009

%E a(18)-a(20) from _Giovanni Resta_, Jul 11 2013

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 21 06:35 EDT 2021. Contains 347596 sequences. (Running on oeis4.)