The On-Line Encyclopedia of Integer Sequences (OEIS)

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A212666 revision #7

A212666

Numbers such that the greatest prime divisor is less than the product of the other distinct prime divisors.

30, 60, 70, 90, 105, 120, 140, 150, 154, 165, 180, 182, 195, 210, 231, 240, 270, 273, 280, 286, 300, 308, 315, 330, 350, 357, 360, 364, 374, 385, 390, 399, 418, 420, 429, 442, 450, 455, 462, 480, 490, 494, 495, 510, 525, 540, 546, 560, 561, 570, 572, 585, 595

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..10000

EXAMPLE

30 is in the sequence because 30 = 2*3*5 and 5 < 2 * 3 = 6.

MAPLE

with(numtheory):for n from 2 to 600 do:x:=factorset(n):m:=nops(x): p:=product( '

x[i] ', 'i'=1..m): q:=p/x[m]:if x[m] < q then printf(`%d, `, n):else fi:od:

CROSSREFS

Sequence in context: A267967 A051283 A066031 * A291046 A071140 A221054

Adjacent sequences: A212663 A212664 A212665 * A212667 A212668 A212669

KEYWORD

nonn

AUTHOR

Michel Lagneau, May 23 2012

STATUS

approved