OFFSET
1,2
COMMENTS
a(27) > 10^11. 3972961263797 is also a term. - Donovan Johnson, May 31 2013
a(30) > 10^13. - Giovanni Resta, Jun 05 2013
EXAMPLE
4909369 + sigma(4909369) = 9823289 and 4909369 + phi(4909369) = 9814189.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
a(17)-a(26) from Donovan Johnson, Oct 05 2010
a(27)-a(29) from Giovanni Resta, Jun 05 2013
STATUS
approved