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A201457
Least k such that (7^n + k)*7^n - 1 is a prime number.
0
5, 11, 1, 11, 23, 29, 17, 31, 13, 37, 61, 11, 35, 149, 17, 151, 17, 17, 17, 13, 59, 17, 73, 47, 43, 13, 113, 77, 119, 97, 125, 83, 13, 421, 103, 103, 77, 23, 23, 79, 5, 107, 7, 37, 59, 113, 11, 1, 169, 887, 137, 41, 113, 71, 277, 413, 97, 91, 227, 337, 97, 353, 233, 953, 5, 139, 77, 473, 73, 167, 275, 67, 49, 97, 365, 73, 223, 241, 115
OFFSET
1,1
MATHEMATICA
Table[k = 0; While[!PrimeQ[(7^n + k)*7^n - 1], k++]; k, {n, 85}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Dec 01 2011
STATUS
approved