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!)
A035033 Numbers n such that n <= d(n)^2, where d() = number of divisors (A000005). 18
1, 2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 48, 54, 56, 60, 72, 80, 84, 90, 96, 108, 120, 126, 132, 140, 144, 168, 180, 192, 210, 216, 240, 252, 288, 300, 336, 360, 420, 480, 504, 540, 720, 840, 1260 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..54.

MATHEMATICA

Select[Range[1300], #<=DivisorSigma[0, #]^2&] (* Harvey P. Dale, Mar 16 2012 *)

PROG

(PARI) is(n)=numdiv(n)^2>=n \\ Charles R Greathouse IV, Aug 03 2012

CROSSREFS

Cf. A000005, A035034, A035035, A033950, A036763, A034884, A273323.

Sequence in context: A225730 A256389 A225729 * A054220 A196277 A280196

Adjacent sequences:  A035030 A035031 A035032 * A035034 A035035 A035036

KEYWORD

nonn,fini,full

AUTHOR

Erich Friedman, Labos Elemer

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 February 24 06:13 EST 2020. Contains 332199 sequences. (Running on oeis4.)