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A280246

a(n) = Product_{d|n} psi(d), where psi(m) is the sum of totatives of m (A023896).

1, 1, 3, 4, 10, 18, 21, 64, 81, 200, 55, 1728, 78, 882, 1800, 4096, 136, 26244, 171, 64000, 7938, 6050, 253, 2654208, 2500, 12168, 19683, 592704, 406, 25920000, 465, 1048576, 54450, 36992, 88200, 544195584, 666, 58482, 109512, 327680000, 820, 504094752, 903

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OFFSET

1,3

COMMENTS

a(n) = n only for n = 1, 3 and 4.

n divides a(n) for all n except 2.

Conjecture: a(n) is odd iff the sum of totatives of n (A023896) is odd.

LINKS

Table of n, a(n) for n=1..43.

FORMULA

a(n) = Product_{d|n} A023896(d).

EXAMPLE