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A113540 a(n) is the minimal k such that 5^n +/- k are primes. 0
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 (list; graph; refs; listen; history; text; internal format)
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: A165822 A014965 A074259 * A111658 A105692 A107647

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

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Last modified December 14 12:04 EST 2019. Contains 329979 sequences. (Running on oeis4.)