OFFSET
1,1
COMMENTS
If n=product p_i^a_i, d=product p_i^c_i is a unitary divisor of n if each c_i is 0 or a_i.
REFERENCES
R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Sect. B7.
LINKS
Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006, Table of n, a(n) for n = 1..44
David Moews, Perfect, amicable and sociable numbers.
J. O. M. Pedersen, Tables of Aliquot Cycles. [Broken link]
J. O. M. Pedersen, Tables of Aliquot Cycles. [Via Internet Archive Wayback-Machine]
J. O. M. Pedersen, Tables of Aliquot Cycles. [Cached copy, pdf file only]
Eric Weisstein's World of Mathematics, Sociable Numbers.
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006
STATUS
approved