121142domain: NAppears in sequencesNumbers n such that 141*2^n-1 is prime.at n=28A050596a(n) = n base 5, under morphism f(1) = 121, f(2) = 123, f(3) = 141, f(4) = 142, or 0 if n base 5 has a zero.at n=8A137850