OFFSET
1,1
LINKS
Harvey Heinz, pattern and program
FORMULA
Arrange 9 consecutive primes in a 3 X 3 grid wherein IBC, HAD, GFE are the first, second and third rows of horizontal primes. Then sum the rows horizontally, vertically and along the two main diagonals. Total the 8 sums, divide by 8 and if the mean is integral and prime, add to the sequence.
EXAMPLE
a(1)=3 because 3 is the first of 9 primes arranged in a 3 X 3 grid wherein the mean of all 8 sums is 41, prime
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, May 05 2004
STATUS
approved