First triangular number with digit sum = n-th triangular number.

A068133

First triangular number with digit sum = n-th triangular number.

Terms

    a(0) =0a(1) =1a(2) =3a(3) =6a(4) =28a(5) =78a(6) =1596a(7) =5995a(8) =67896a(9) =887778a(10) =15997996a(11) =398988876a(12) =9876799878a(13) =299789989975

External references