OFFSET
1,1
EXAMPLE
a(4)= 10781 belongs to the emirp pair (10781, 18701) whose average is the palindromic prime 14741 = A178581(4) which is also the arithmetic mean of the other emirp pair (13751, 15731).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, May 29 2010
EXTENSIONS
Extended by Ray Chandler, Jul 05 2010
STATUS
approved