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A063972 a(n) is the smallest m such that usigma(m) = n (or 0 if no such m). 1
1, 0, 2, 3, 4, 5, 0, 7, 8, 9, 0, 6, 0, 13, 0, 0, 16, 10, 0, 12, 0, 0, 0, 14, 0, 25, 0, 27, 0, 18, 0, 21, 32, 0, 0, 22, 0, 37, 0, 28, 0, 26, 0, 43, 0, 0, 0, 33, 0, 36, 0, 0, 0, 34, 0, 39, 0, 0, 0, 38, 0, 61, 0, 0, 64, 0, 0, 48, 0, 52, 0, 30, 0, 73, 0, 0, 0, 50, 0, 57, 0, 81, 0, 54, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

usigma(m) is the sum of unitary divisors of m, A034448.

LINKS

Table of n, a(n) for n=1..89.

EXAMPLE

a(12)=6 because the unitary divisors of 6 are 1,2,3,6; they sum to 12.

CROSSREFS

Cf. A034444, A034448, A051444, A057637, A063973.

Sequence in context: A267000 A224892 A265517 * A063973 A126441 A004181

Adjacent sequences:  A063969 A063970 A063971 * A063973 A063974 A063975

KEYWORD

nonn

AUTHOR

Labos Elemer, Sep 05 2001

EXTENSIONS

Edited by Don Reble, May 14 2006

STATUS

approved

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Last modified June 17 22:17 EDT 2019. Contains 324200 sequences. (Running on oeis4.)