1,2

Also, numbers n such that (20+20*(9*n-1)*10^n-81*(n^2+n))/1458 + 1 is prime.

Table of n, a(n) for n=1..6.

Sequence in context: A154493 A031012 A188075 * A270710 A110341 A317614

Adjacent sequences: A121911 A121912 A121913 * A121915 A121916 A121917

more,nonn

Jason Earls, Sep 02 2006

approved