A120820 a(n) consecutive digits ascending beginning with the digit 2 give a prime.

1, 2, 8, 82, 118, 158, 2122, 2242, 2388

Offset: 1

Author

Robert G. Wilson v, Jul 05 2006

Keywords

• nonn
• base
• hard
• more

Comments

Digits are in ascending order beginning with 2 and after 9 comes 0.

The sequence "a(n) consecutive digits descending beginning with the digit 2 give a prime" has only one term, 1 which represents the prime 2.

a(10) > 10^5. - Michael S. Branicky, Apr 10 2025

Examples

			8 is a term since 23456789 is a prime.
		

Crossrefs

Cf. A006055, A120819, A120821, A120822, A120823, A120824, A120825, A120826, A120827.

Programs

Mathematica

fQ[n_] := PrimeQ@ FromDigits@ Mod[1+Range@n, 10]; lst = {}; Do[ If[fQ@n, AppendTo[lst, n]; Print@n], {n, 10000}]; lst