OFFSET
2,2
COMMENTS
Subsequence of A001818.
a(n) is congruent to 1 or -1 (modulo the n-th prime).
REFERENCES
Kenneth Rosen, Elementary Number Theory and its Applications, Addison Wesley, page 223.
EXAMPLE
a(4)= 225 because the 4th prime number is 7 and 1^2*3^2*5^2 = 225. 225 is congruent to 1 (mod 7).
MATHEMATICA
Table[Product[(Prime[n] - 2i)^2, {i, n}], {n, 2, 15}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, Nov 01 2012
STATUS
approved