a(1) = 9; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n).
A068624
a(1) = 9; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n).
Terms
- a(0) =9a(1) =91a(2) =1891a(3) =18915a(4) =1989015a(5) =199890015a(6) =19998900015
External references
- oeis: A068624