OFFSET
6,1
COMMENTS
a(10) > 2^31. a(11) = 1143502909. - Arkadiusz Wesolowski, Apr 29 2012
LINKS
EXAMPLE
271129 has the covering set {3, 5, 7, 13, 17, 241}.
78557 has the covering set {3, 5, 7, 13, 19, 37, 73}.
1777613 has the covering set {3, 5, 7, 13, 17, 19, 109, 433}.
169073869 has the covering set {3, 5, 7, 11, 13, 41, 61, 151, 331}.
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Arkadiusz Wesolowski, Feb 10 2012
STATUS
approved