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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A278569 Numbers of the form p^i*q^j*r^k where p,q,r are distinct odd primes and i,j,k >= 1. 3
105, 165, 195, 231, 255, 273, 285, 315, 345, 357, 385, 399, 429, 435, 455, 465, 483, 495, 525, 555, 561, 585, 595, 609, 615, 627, 645, 651, 663, 665, 693, 705, 715, 735, 741, 759, 765, 777, 795, 805, 819, 825, 855, 861, 885, 897, 903, 915, 935, 945, 957, 969, 975, 987, 1001, 1005, 1015, 1023, 1035, 1045, 1065, 1071, 1085, 1095, 1105, 1113, 1131, 1173, 1185, 1197, 1209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

More than the usual number of terms are included to show the difference from A216918 (the latter includes 3*5*7*11 = 1155 and all terms of A046390, A046391 etc).

If i,j,k are all equal to 1 we get A046389.

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

FORMULA

A033992 INTERSECT A005408. - R. J. Mathar, Dec 05 2016

MATHEMATICA

Select[Range@ 1500, PrimeNu@ # == 3 && OddQ@ # &] (* Michael De Vlieger, Dec 05 2016 *)

CROSSREFS

Includes A046389, subsequence of A216918.

Sequence in context: A133509 A013590 A216918 * A046389 A154430 A118678

Adjacent sequences:  A278566 A278567 A278568 * A278570 A278571 A278572

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Nov 27 2016

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 22 09:43 EST 2019. Contains 320390 sequences. (Running on oeis4.)