A048404 Primes with consecutive digits that differ exactly by 7.

2, 3, 5, 7, 29, 181, 929, 18181, 929292929, 18181818181818181818181818181818181818181818181818181818181818181818181818181

Offset

1,1

Comments

The next term (a(11)) has 163 digits. - Harvey P. Dale, Mar 23 2023

Links

Sean A. Irvine, Table of n, a(n) for n = 1..13

Mathematica

Module[{s18, s81, s29, s92}, s18=Select[Table[FromDigits[PadRight[{}, n, {1, 8}]], {n, 1, 181, 2}], PrimeQ]; s81=Select[Table[FromDigits[PadRight[{}, n, {8, 1}]], {n, 2, 182, 2}], PrimeQ]; s29 = Select[ Table[FromDigits[PadRight[{}, n, {2, 9}]], {n, 2, 182, 2}], PrimeQ]; s92 =Select[Table[ FromDigits[ PadRight[{}, n, {9, 2}]], {n, 1, 183, 2}], PrimeQ]; Join[{2, 3, 5, 7}, s18, s81, s29, s92]//Sort] (* Harvey P. Dale, Mar 23 2023 *)

Crossrefs

Cf. A048398, A048399, A048400, A048401, A048402, A048403, A048405, A048409.

Sequence in context: A090712 A082257 A054750 * A052013 A269022 A174536

Adjacent sequences: A048401 A048402 A048403 * A048405 A048406 A048407

Keyword

nonn,base

Author

Patrick De Geest, Apr 15 1999

Status

approved