A096186 Numbers n such that 10^n+9^(n-1) is prime.

1, 2, 4, 9, 12, 14, 19, 26, 28, 72, 79, 273, 565, 990, 1166, 2205, 4212, 5340, 5562, 9877, 10297, 14316, 35908, 48410, 61525

Offset

1,2

Comments

a(26) > 10^5. - Robert Price, Mar 28 2016

Links

Table of n, a(n) for n=1..25.

Mathematica

Do[ If[ PrimeQ[10^n + 9^(n - 1)], Print[n]], {n, 4000}]

Prog

(PARI) is(n)=isprime(10^n+9^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Crossrefs

Cf. A082103, A093717, A093793, A093765, A096185, A093794, A093795, A096186.

Sequence in context: A058885 A256446 A022428 * A359817 A175041 A352342

Adjacent sequences: A096183 A096184 A096185 * A096187 A096188 A096189

Keyword

nonn

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net) and Robert G. Wilson v, Jun 21 2004

Extensions

a(17)-a(25) from Robert Price, Mar 28 2016

Status

approved