A113540 a(n) is the minimal k such that 5^n +/- k are primes.

2, 6, 12, 6, 42, 18, 66, 126, 144, 762, 78, 318, 1026, 84, 264, 354, 288, 102, 1242, 162, 168, 318, 2058, 234, 2352, 252, 2532, 42, 342, 102, 2034, 2946, 222, 606, 882, 348, 3366, 2472, 264, 2988, 2466, 336, 666, 762, 222, 438, 3432, 6834, 3816, 588, 1818

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Example

a(1)=2 because 5^1 +/- 2 are primes; a(2)=6 because 5^2 +/- 6 are primes.

Mathematica

f[n_] := Block[{k = 2}, While[ ! PrimeQ[5^n + k] || ! PrimeQ[5^n - k], k += 2]; k]; Array[f, 51] (* Robert G. Wilson v *)

Crossrefs

Sequence in context: A014965 A074259 A338376 * A111658 A341664 A105692

Adjacent sequences: A113537 A113538 A113539 * A113541 A113542 A113543

Keyword

nonn

Author

Zak Seidov, Jan 13 2006

Extensions

Corrected and extended by Robert G. Wilson v, Jan 18 2006

Status

approved