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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

%I

%S 36,3600,8100,10000,26244,32400,142884,202500,396900,518400,656100,

%T 810000,1587600,1679616,2286144,2624400,3572100,6350400,9144576,

%U 9922500,20575296

%N 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.

%C Note that s is necessarily a multiple of r.

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

%Y Cf. A033950, A049439. A057265.

%K nonn

%O 1,1

%A _Walter Kehowski_, Jun 25 2006

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Last modified November 12 12:43 EST 2018. Contains 317109 sequences. (Running on oeis4.)