OFFSET
1,1
COMMENTS
EXAMPLE
a(1) = 2 because there are just two single-digit primes to start a prime 5-tuple, namely 5 = A022006(1) and 7 = A022007(1).
a(2) = 2 because 11 = A022006(2) and 97 = A022007(2) are the only two two-digit primes to start a prime 5-tuple.
a(3) = 1 because there is only one three-digit prime to start a prime 5-tuple, namely 101 = A022006(3).
Then there are a(4) = 4 four-digit primes, 1481, 1867, 3457 and 5647, which start a prime 5-tuple.
PROG
CROSSREFS
KEYWORD
nonn,base,hard,more
AUTHOR
M. F. Hasler, Mar 01 2022
STATUS
approved