Least number with identical digits such that the concatenation a(n) a(n-1) ...a(2)a(1) a(2) ... a(n-1) a(n) is a prime.
A090276
Least number with identical digits such that the concatenation a(n) a(n-1) ...a(2)a(1) a(2) ... a(n-1) a(n) is a prime.
Terms
- a(0) =2a(1) =7a(2) =3a(3) =33a(4) =9a(5) =77a(6) =33a(7) =999a(8) =1111111a(9) =3a(10) =33a(11) =777777a(12) =111111111a(13) =77a(14) =333333a(15) =111a(16) =99999999a(17) =3333333333a(18) =777777a(19) =1a(22) =99999999
External references
- oeis: A090276