OFFSET
1,1
COMMENTS
The unitary version of A057978. a(5)-a(8) were taken from the paper by Pomerance and Yang.
LINKS
Carl Pomerance and Hee-Sung Yang, Variant of a theorem of Erdős on the sum-of-proper-divisors function, Mathematics of Computation, Vol. 83, No. 288 (2014), pp. 1903-1913.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Jul 24 2017
STATUS
approved