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

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A162142 Numbers that are the cube of a product of two distinct primes (p^3*q^3). 10
216, 1000, 2744, 3375, 9261, 10648, 17576, 35937, 39304, 42875, 54872, 59319, 97336, 132651, 166375, 185193, 195112, 238328, 274625, 328509, 405224, 456533, 551368, 614125, 636056, 658503, 753571, 804357, 830584, 857375, 1191016, 1367631, 1520875, 1643032 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subset of A046306, of A000578, and of A007774. - R. J. Mathar, Jun 27 2009

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Index to sequences related to prime signature

FORMULA

a(n) = (A006881(n))^3 = A000578(A006881(n)). - R. J. Mathar, Jun 27 2009

EXAMPLE

216=2^3*3^3. 1000=2^3*5^3. 2744=2^3*7^3.

MATHEMATICA

fQ[n_]:=Last/@FactorInteger[n]=={3, 3}; lst={}; Do[If[fQ[n], AppendTo[lst, n]], {n, 6*9!}]; lst

CROSSREFS

Sequence in context: A111029 A124581 A177493 * A233859 A233853 A245993

Adjacent sequences:  A162139 A162140 A162141 * A162143 A162144 A162145

KEYWORD

nonn,changed

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jun 25 2009

EXTENSIONS

Definition rephrased by R. J. Mathar, Jun 27 2009

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 29 21:28 EDT 2017. Contains 287257 sequences.