A177141 Primes of the form (6*10^k-7)

53, 593, 599993, 5999993, 59999993, 599999999993, 599999999999999993, 599999999999999999999999999993, 5999999999999999999999999999999999999999993, 599999999999999999999999999999999999999999999993

Offset

1,1

Comments

The next term -- a(11) -- has 97 digits. - Harvey P. Dale, Nov 15 2021

Links

Robert Israel, Table of n, a(n) for n = 1..15

Formula

a(n) = 6 * 10^A103025(n) - 7. - Robert Israel, Jan 22 2024

Maple

select(isprime, [seq(6*10^k-7, k=1..100)]); # Robert Israel, Jan 22 2024

Mathematica

able[10 FromDigits[PadRight[{5}, n, 9]]+3, {n, 50}], PrimeQ] (* Harvey P. Dale, Nov 15 2021 *)

Prog

(Magma) [a: n in [0..250]|IsPrime(a) where a is 6*10^n-7]

Crossrefs

Cf. A103025.

Sequence in context: A201855 A112749 A245589 * A096707 A219989 A027007

Adjacent sequences: A177138 A177139 A177140 * A177142 A177143 A177144

Keyword

nonn

Author

Vincenzo Librandi, Dec 10 2010

Status

approved