OFFSET
1,2
COMMENTS
To get the total number of solutions including rotations and reflections, multiply a(n) by 8.
EXAMPLE
a(1) = 0 because there is no 3 X 3 square arrangement of the primes 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29 such that all row, column and diagonal totals are primes. a(2) = 116 because there are 116 unique 3 X 3 square arrangements of the primes 3, 5, 7, 11, 13, 17, 19, 23 and 29 such that all row, column and diagonal totals are primes. Here is one solution counted by a(2):
+----+----+----+
| 3 | 5 | 11 | --> 19
+----+----+----+
| 17 | 7 | 13 | --> 37
+----+----+----+
| 23 | 29 | 19 | --> 71
+----+----+----+
/ vv vv vv \
41 43 41 43 29
CROSSREFS
KEYWORD
nonn
AUTHOR
Chuck Seggelin (seqfan(AT)plastereddragon.com), Jul 31 2004
STATUS
approved