A159352 Primes of the form "1 [0]_n 3" - with zeros between 1 and 3.

13, 103, 100003, 1000003, 100000000003, 100000000000000003, 1000000000000000003, 1000000000000000000000000000000000000003, 100000000000000000000000000000000000000000000000000000003

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Dario Alejandro Alpern, Factorization using the Elliptic Curve Method

Makoto Kamada, Prime numbers of the form 100...003.

Index entries for primes involving repunits.

Example

1000000000000000000000000000000000000003 is a prime with 38 zeros between 1 and 3.

Maple

select(isprime, [seq(10^k+3, k=1..998)]); # Robert Israel, Dec 28 2015

Prog

(Magma) [p: n in [1..100] | IsPrime(p) where p is 10^n+3 ]; // Klaus Brockhaus, Apr 12 2009

Crossrefs

Cf. A159031.

Cf. A049054 (numbers n such that 10^n + 3 is prime), A102006 (numbers n such that 10*10^n + 3 is prime), A011557 (powers of 10).

Sequence in context: A100277 A087398 A080440 * A289859 A129762 A283121

Adjacent sequences: A159349 A159350 A159351 * A159353 A159354 A159355

Keyword

base,nonn

Author

Parthasarathy Nambi, Apr 11 2009

Status

approved