A103045 - OEIS

A103045

Numbers n such that 6*10^n + 8*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

2, 3, 8, 50, 56, 72, 108, 132, 182, 1100, 1368, 1605, 5132, 22682

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OFFSET

1,1

COMMENTS

Also numbers n such that (62*10^n-53)/9 is prime.

a(15) > 10^5. - Robert Price, Sep 15 2015

LINKS

FORMULA

a(n) = A101538(n) + 1.

MATHEMATICA

Do[ If[ PrimeQ[(62*10^n - 53)/9], Print[n]], {n, 0, 10000}]

CROSSREFS

KEYWORD

more,nonn

AUTHOR

EXTENSIONS

a(14) from Kamada data by Robert Price, Dec 14 2010

STATUS

approved