

A242824


Primes formed by the initial digits of the decimal expansion of 1/7, starting at the first nonzero digit in the expansion.


4




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


LINKS

Table of n, a(n) for n=1..2.


MATHEMATICA

Select[Table[FromDigits[PadRight[{}, 6n+1, {1, 4, 2, 8, 5, 7}]], {n, 200}], PrimeQ](* Harvey P. Dale, Oct 03 2018 *)


CROSSREFS

Cf. A020806, A241217.
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 A234657
Adjacent sequences: A242821 A242822 A242823 * A242825 A242826 A242827


KEYWORD

nonn,base,bref


AUTHOR

Felix FrÃ¶hlich, May 23 2014


STATUS

approved



