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A242824
Primes formed by the initial digits of the decimal expansion of 1/7, starting at the first nonzero digit in the expansion.
4
1428571, 1428571428571428571428571
OFFSET
1,1
COMMENTS
Next term has 355 digits.
All terms are of the form 6x+1; a(4) has 823 digits; and there are no further terms up to and including 10000 digits. - Harvey P. Dale, Oct 03 2018
MATHEMATICA
Select[Table[FromDigits[PadRight[{}, 6n+1, {1, 4, 2, 8, 5, 7}]], {n, 200}], PrimeQ](* Harvey P. Dale, Oct 03 2018 *)
CROSSREFS
Corresponding sequences for 1/k: A093676 (k=12), A242826 (k=13), A242827 (k=14), A242828 (k=17), A242833 (k=19).
Sequence in context: A301557 A186837 A054852 * A204288 A321040 A345614
KEYWORD
nonn,base,bref
AUTHOR
Felix Fröhlich, May 23 2014
STATUS
approved