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A230577 Positive integers that have exactly 6 odd divisors. 8
45, 63, 75, 90, 99, 117, 126, 147, 150, 153, 171, 175, 180, 198, 207, 234, 243, 245, 252, 261, 275, 279, 294, 300, 306, 325, 333, 342, 350, 360, 363, 369, 387, 396, 414, 423, 425, 468, 475, 477, 486, 490 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers that can be formed in exactly 5 ways by summing sequences of 2 or more consecutive integers.

Column 6 of A266531. - Omar E. Pol, Apr 03 2016

Numbers n such that the symmetric representation of sigma(n) has 6 subparts. - Omar E. Pol, Dec 28 2016

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[500], Count[Divisors[#], _?OddQ]==6&] (* Harvey P. Dale, Mar 25 2015 *)

PROG

(PARI) is(n)=numdiv(n>>valuation(n, 2))==6 \\ Charles R Greathouse IV, Oct 28 2013

CROSSREFS

Cf. A000203, A001227, A077646, A237593, A279387, A266531.

Numbers with k odd divisors (k = 1..10): A000079, A038550, A072502, apparently A131651, A267696, this sequence, A267697, A267891, A267892, A267893.

Sequence in context: A242263 A242264 A077646 * A175761 A046364 A051773

Adjacent sequences:  A230574 A230575 A230576 * A230578 A230579 A230580

KEYWORD

nonn

AUTHOR

Philippe Beaudoin, Oct 23 2013

STATUS

approved

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Last modified September 22 15:16 EDT 2018. Contains 315270 sequences. (Running on oeis4.)