A063973 a(n) is the largest m such that usigma(m) = n (or 0 if no such m).

1, 0, 2, 3, 4, 5, 0, 7, 8, 9, 0, 11, 0, 13, 0, 0, 16, 17, 0, 19, 0, 0, 0, 23, 0, 25, 0, 27, 0, 29, 0, 31, 32, 0, 0, 24, 0, 37, 0, 28, 0, 41, 0, 43, 0, 0, 0, 47, 0, 49, 0, 0, 0, 53, 0, 39, 0, 0, 0, 59, 0, 61, 0, 0, 64, 0, 0, 67, 0, 52, 0, 71, 0, 73, 0, 0, 0, 50, 0, 79, 0, 81, 0, 83, 0, 0, 0, 0

Offset

1,3

Comments

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

Links

Daniel Suteu, Table of n, a(n) for n = 1..10000

Example

a(12)=11 because the unitary divisors of 11 are 1,11; they sum to 12.

Crossrefs

Cf. A034444, A034448, A051444, A057637, A063972.

Sequence in context: A351233 A265517 A063972 * A126441 A004181 A080744

Adjacent sequences: A063970 A063971 A063972 * A063974 A063975 A063976

Keyword

nonn

Author

Labos Elemer, Sep 05 2001

Extensions

Corrected by Don Reble, May 14 2006

Status

approved