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A048405
Primes with consecutive digits that differ exactly by 8.
12
2, 3, 5, 7, 19, 191, 919, 919191919, 91919191919, 91919191919191919, 91919191919191919191919, 191919191919191919191919191919191
OFFSET
1,1
COMMENTS
The next term (a(13)) has 133 digits. - Harvey P. Dale, Jan 04 2023
LINKS
EXAMPLE
2 is a term since all its consecutive digits differ by 5 (there aren't any).
19 is a term because 1 and 9 differ by 8.
23 is not a term because its consecutive digits differ only by 1.
MATHEMATICA
Module[{nn=500, nine, one}, one=Select[Table[FromDigits[PadRight[{}, n, {1, 9}]], {n, nn}], PrimeQ]; nine=Select[Table[FromDigits[PadRight[{}, n, {9, 1}]], {n, nn}], PrimeQ]; Sort[Join[{2, 3, 5, 7}, nine, one]]] (* Harvey P. Dale, Jan 04 2023 *)
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Apr 15 1999
EXTENSIONS
Offset corrected by Sean A. Irvine, Jun 16 2021
STATUS
approved