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A166722 a(n) is the number of divisors of A166721(n). 2


%S 1,3,5,9,7,15,21,27,11,25,45,13,35,33,63,75,39,81,49,17,55,105,135,99,

%T 19,65,51,189,77,125,117,147,225,165,57,243,91,175,23,85,315,195,297,

%U 153,231,95,405,245,69,375,351,119,275,441,171,121,273,567,495,255,525

%N a(n) is the number of divisors of A166721(n).

%C This is a permutation of the odd numbers A005408. - _Alois P. Heinz_, Mar 04 2018

%H Alois P. Heinz, <a href="/A166722/b166722.txt">Table of n, a(n) for n = 1..300</a>

%e a(8) = A000005(A166721(8)) = A000005(900) = A000005(2^2 * 3^2 * 5^2) = (2+1)*(2+1)*(2+1) = 27.

%Y Cf. A000005, A005408, A048691, A136404, A152674, A166721.

%K easy,nonn

%O 1,2

%A Alexander Isaev (i2357(AT)mail.ru), Oct 20 2009

%E Proper definition (and removal of obscure Comments entries) by _Jon E. Schoenfield_, Mar 03 2018

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Last modified January 20 19:53 EST 2020. Contains 331096 sequences. (Running on oeis4.)