OFFSET
1,2
EXAMPLE
The initial 1 is from the prime 11.
a(4)=1180 because to 10^4 or 10000 primes, ending in 104729=A006988(4), there are 1180 primes with equal and distinct first and last digits: 1 and 1, 3 and 3, 7 and 7 and 9 and 9.
CROSSREFS
KEYWORD
hard,more,nonn,base
AUTHOR
Enoch Haga, Oct 16 2008
EXTENSIONS
Edited by N. J. A. Sloane, Aug 16 2010
a(6) corrected and a(7)-a(10) added by D. S. McNeil, Aug 29 2010
STATUS
approved