OFFSET
1,2
COMMENTS
The partial product is a multiple of n!.
EXAMPLE
a(5) = 25 as 1*2*3*12*25 + 1= 1801 is a prime but 1*2*3*12*k + 1 is not a prime for k = 5,10,15 and 20.
MATHEMATICA
a[1] = 1; a[n_] := a[n] = Block[{k = 1, pp = Product[a[i], {i, 1, n - 1}]}, While[ !PrimeQ[ pp*k*n + 1], k++ ]; k*n]; Table[ a[n], {n, 1, 54}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 13 2003
EXTENSIONS
Edited and extended by Robert G. Wilson v, Jun 15 2003
STATUS
approved