OFFSET
1,1
COMMENTS
The smallest k for which sigma(k) = sopf(k)^6 is 45770980141656. Other such values are 5245619666623908 and 5582294774581035.
LINKS
Robert Gerbicz, Table of n, a(n) for n = 1..10000
EXAMPLE
213556659624 = 2^3*3^3*7^3*11*31*79*107 and sigma(213556659624) = (2+3+7+11+31+79+107)^5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Jan 07 2013
STATUS
approved