OFFSET
1,2
COMMENTS
This is a subsidiary sequence suggested in A088104.
LINKS
Tomás Oliveira e Silva, Tables of values of pi(x) and of pi2(x)
EXAMPLE
a(2) = 2 since 23 and 29 are the only two 2-digit primes beginning with 2.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ray Chandler, Oct 15 2003
EXTENSIONS
More terms from Harvey P. Dale, Oct 16 2003
a(10)-a(13) corrected and a(14)-a(22) from Donovan Johnson, Apr 24 2013
Incorrect Mathematica program deleted by Harvey P. Dale, Apr 25 2013
a(23) from Chai Wah Wu, Jun 20 2019
STATUS
approved