A064214 Least k such that k*5^n +/- 1 are twin primes.

4, 6, 6, 24, 42, 42, 18, 198, 42, 54, 96, 84, 522, 240, 48, 228, 708, 732, 660, 132, 528, 390, 78, 1014, 504, 1008, 1134, 504, 708, 582, 894, 516, 2982, 810, 162, 1746, 4758, 1848, 414, 4512, 2928, 1722, 4392, 1104, 1134, 1950, 390, 78, 1500, 300, 60

Offset

0,1

Links

Table of n, a(n) for n=0..50.

Mathematica

Do[ k = 1; While[ ! PrimeQ[ k*5^n + 1 ] || ! PrimeQ[ k*5^n - 1 ], k++ ]; Print[ k ], {n, 0, 50} ]

Crossrefs

Cf. A063983.

Sequence in context: A019090 A145692 A295512 * A019203 A365084 A082237

Adjacent sequences: A064211 A064212 A064213 * A064215 A064216 A064217

Keyword

nonn

Author

Robert G. Wilson v, Sep 21 2001

Extensions

Offset corrected by Georg Fischer, May 01 2022

Status

approved