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!)
A145681 Numbers m such that A034448(m) = 3m/2, where A034448 = unitary sigma = sum of divisors d with gcd(d,m/d)=1. 1

%I #12 Jan 02 2023 12:30:47

%S 2,20,24,360,816,1056,12240,15840,29120,181632,2724480,9192960,

%T 13790400,15288000,93358848,199180800,1130734080,1400382720,

%U 25115166720,544161945600,3089165506560,11519246340096,172788695101440,274358081249280,5944425093734400,33746043993661440,7425442423511040000,25976914334122752000000,48787315395486187520000,56897897650906642513920

%N Numbers m such that A034448(m) = 3m/2, where A034448 = unitary sigma = sum of divisors d with gcd(d,m/d)=1.

%C See also A144672, A144673 and A144674. These three and the present one all differ only by one or two terms around a(11)-a(12). More explanations would be welcome. - _M. F. Hasler_, Jan 29 2014

%H Y. Kohmoto, <a href="http://list.seqfan.eu/oldermail/seqfan/2014-January/012386.html">Unitary RMPN</a>, SeqFan list, Jan. 2014

%Y Cf. A034448.

%K nonn

%O 1,1

%A _Yasutoshi Kohmoto_ Mar 09 2009

%E Corrected and extended by _Jack Brennen_, Jan 30 2014

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 April 26 21:53 EDT 2024. Contains 372004 sequences. (Running on oeis4.)