Semiprimes that are the concatenation of n 1's, 2^n and n 1's.
A261364
Semiprimes that are the concatenation of n 1's, 2^n and n 1's.
Terms
- a(0) =121a(1) =1118111a(2) =1111161111
External references
- oeis: A261364
A261364
Semiprimes that are the concatenation of n 1's, 2^n and n 1's.