1,3

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

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

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

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

Sequence in context: A267000 A224892 A265517 * A063973 A126441 A004181

Adjacent sequences: A063969 A063970 A063971 * A063973 A063974 A063975

nonn

Labos Elemer, Sep 05 2001

Edited by Don Reble, May 14 2006

approved