A196225 - OEIS

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A196225

Smallest number k such that sigma(tau(k)) = n, or 0 if there is no such k.

1, 0, 2, 4, 0, 16, 6, 64, 0, 0, 0, 12, 36, 4096, 24, 0, 0, 48, 0, 262144, 0, 0, 0, 192, 0, 0, 0, 60, 0, 268435456, 120, 576, 0, 0, 0, 3072, 0, 68719476736, 180, 900, 0, 240, 0, 4398046511104, 0, 0, 0, 9216, 0, 0, 0, 0, 0, 196608, 0, 960, 46656, 0, 0, 360, 0, 1152921504606846976

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OFFSET

1,3

COMMENTS

Smallest number k such that A062069(k) = A000203(A000005(k)) = n, or 0 if there is no such k.

LINKS

Table of n, a(n) for n=1..62.

FORMULA

a(n)=0 iff A051444(n) = 0.

EXAMPLE

a(6) = 16 because number 16 is the smallest number k such that sigma(tau(k)) = 6; (tau(16)=5, sigma(5)=6).

CROSSREFS