a(1) = 7; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n).

A068621

a(1) = 7; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n).

Terms

    a(0) =7a(1) =78a(2) =378a(3) =1378a(4) =91378a(5) =7791378a(6) =707914378

External references