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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A121556 Numbers such that sigma(n)^2 is divisible by UnitarySigma(n)*UnitaryPhi(n). 4
1, 2, 3, 6, 14, 15, 30, 35, 42, 70, 78, 105, 190, 210, 348, 357, 418, 570, 714, 910, 1045, 1144, 1254, 2090, 2296, 2730, 3135, 3432, 4060, 4522, 4674, 5278, 6270, 6888, 10168, 10659, 10824, 12180, 12441, 13566, 14630, 15834, 16770, 17160 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

MAPLE

for n from 1 to 20000 do if numtheory[sigma](n)^2 mod (A047994(n)*A034448(n)) = 0 then printf("%d, ", n) ; end if; end do:

CROSSREFS

Cf. A121647, A078557, A020492, A034448, A047994.

Sequence in context: A030733 A122839 A258077 * A123041 A078557 A005537

Adjacent sequences:  A121553 A121554 A121555 * A121557 A121558 A121559

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto, Sep 12 2006

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 November 15 01:25 EST 2019. Contains 329143 sequences. (Running on oeis4.)