A201131 Least k such that (5^n - k)*5^n + 1 is a prime number.

3, 1, 11, 1, 5, 19, 9, 1, 11, 15, 9, 69, 27, 21, 77, 85, 53, 1, 5, 201, 9, 43, 93, 403, 45, 87, 17, 63, 45, 15, 23, 9, 17, 273, 51, 31, 111, 277, 45, 39, 51, 229, 9, 109, 29, 357, 81, 1, 237, 33, 137, 169, 137, 847, 75, 367, 57, 87, 285, 25, 105, 177, 113, 1

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Mathematica

Table[k = 0; While[!PrimeQ[(5^n - k)*5^n + 1], k++]; k, {n, 85}]

Crossrefs

Cf. A200923, A200923.

Sequence in context: A200652 A276391 A119632 * A277790 A360121 A339175

Adjacent sequences: A201128 A201129 A201130 * A201132 A201133 A201134

Keyword

nonn

Author

Michel Lagneau, Nov 27 2011

Status

approved