OFFSET
1,1
COMMENTS
a(14) > 6.8*10^11. - Giovanni Resta, Dec 16 2013
EXAMPLE
Example: for n = 3, initial prime is 251, because 251 -> 251 - 2*5*1 = 241 -> 241 - 2*4*1 -> 233.
CROSSREFS
KEYWORD
nonn,base,hard
AUTHOR
Carlos Rivera, Dec 15 2013
EXTENSIONS
a(11)-a(13) from Giovanni Resta, Dec 16 2013
STATUS
approved