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A120359 Even refactorable numbers n such that the number r of odd divisors is odd, the number s of even divisors is even, both r and s are divisors of n and n is the first number for which the triple (r,s,t) occurs, where t is the number of divisors of n. 2
36, 3600, 8100, 10000, 26244, 32400, 142884, 202500, 396900, 518400, 656100, 810000, 1587600, 1679616, 2286144, 2624400, 3572100, 6350400, 9144576, 9922500, 20575296 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Note that s is necessarily a multiple of r.

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

a(1)=36 since r=3, s=6 and r+s=9.

CROSSREFS

Cf. A033950, A049439. A057265.

Sequence in context: A072377 A209267 A120349 * A194611 A165984 A297021

Adjacent sequences:  A120356 A120357 A120358 * A120360 A120361 A120362

KEYWORD

nonn

AUTHOR

Walter Kehowski, Jun 25 2006

STATUS

approved

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Last modified August 18 13:28 EDT 2018. Contains 313832 sequences. (Running on oeis4.)