OFFSET
1,2
COMMENTS
"Between 10^(n-1) and 10^n" is equivalent to saying "with n (decimal) digits".
A prime nonuplet is a sequence of 9 consecutive primes (p1, ..., p9) of minimal diameter p9 - p1 = 30.
Terms a(1)-a(11) computed from b-file a(1..651) for A257125.
Apart for n = 1 (cf. EXAMPLE), so far the last term of all the nonuplets has the same number of digits as the initial term.
EXAMPLE
a(1) = 1 because 7 is the only single-digit prime to start a prime nonuplet, i.e., member of A257125. (All other members of this nonuplet have 2 digits.)
a(2) = 3 because 11, 13 and 17 are the three 2-digit primes to start a prime nonuplet.
a(3) = 0 because there is no 3-digit prime initial member of a prime nonuplet.
PROG
CROSSREFS
KEYWORD
nonn,base,hard,more
AUTHOR
M. F. Hasler, Mar 01 2022
STATUS
approved