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!)
A185031 Numbers n (other than powers of 2) such that the absolute value of abundance(n) is a square. 1
5, 6, 12, 14, 17, 28, 37, 38, 44, 70, 88, 92, 98, 101, 108, 110, 134, 152, 168, 170, 172, 197, 206, 220, 248, 257, 284, 348, 374, 398, 401, 410, 428, 434, 496, 550, 577, 580, 590, 604, 632, 638, 677, 726, 748, 752, 798, 884, 910, 918, 952, 974, 988, 1032 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Abundance
MATHEMATICA
lst = {}; e = 10; Do[If[IntegerQ[Abs[DivisorSigma[1, n] - 2*n]^(1/2)], AppendTo[lst, n]], {n, 2^e + e}]; Complement[lst, Table[Power[2, m], {m, 0, e}]]
CROSSREFS
Supersequence of A188484.
Sequence in context: A285404 A047319 A244368 * A138925 A088767 A032707
KEYWORD
nonn
AUTHOR
STATUS
approved

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 June 20 11:48 EDT 2024. Contains 373527 sequences. (Running on oeis4.)