OFFSET
1,2
COMMENTS
When a(n)=1, we get a prime repunit and these indices+1 give A004023. - Michel Marcus, Nov 13 2013
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
EXAMPLE
For n = 2, the numbers to consider are 111, 122, 133, 144, 155, 166, 177, 188, 199,.... The first prime is 199.
MATHEMATICA
Table[k = 1; While[p = FromDigits[Join[{1}, Flatten[Table[IntegerDigits[k], {n}]]]]; ! PrimeQ[p], k = k + 2]; k, {n, 65}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
T. D. Noe, Nov 13 2013
STATUS
approved