221212111

Properties

Appears in sequences

• Prime numbers whose digits are k+1 1's and k 2's for some k >= 1.at n=18A276461
• a(1)=1; thereafter, a(n) = string appended to (n-1)-st generation of A306211 to get the n-th generation.at n=6A323478
• Prime numbersat n=12185513