OFFSET
2,2
LINKS
J.-L. Baril, Classical sequences revisited with permutations avoiding dotted pattern, Electronic Journal of Combinatorics, 18 (2011), #P178.
Thomas R. Nicely, Enumeration to 1.6*10^15 of the prime quadruplets.
EXAMPLE
a(3) = 3 because there are three three-digit prime quadruples: {101, 103, 107, 109}, {191, 193, 197, 199} and {821, 823, 827, 829}.
CROSSREFS
KEYWORD
nonn,more,base
AUTHOR
Julien Peter Benney (jpbenney(AT)ftml.net), Aug 15 2006, Aug 19 2006
EXTENSIONS
a(6) corrected and a(15) supplied by Jon E. Schoenfield, Aug 27 2006
STATUS
approved