a(n) = n 9's sandwiched between two 1's.
A185123
a(n) = n 9's sandwiched between two 1's.
Terms
- a(0) =11a(1) =191a(2) =1991a(3) =19991a(4) =199991a(5) =1999991a(6) =19999991a(7) =199999991a(8) =1999999991a(9) =19999999991a(10) =199999999991
External references
- oeis: A185123