Triangular numbers with arithmetic mean of digits = integer (sum of digits = A multiple of the number of digits).

A069712

Triangular numbers with arithmetic mean of digits = integer (sum of digits = A multiple of the number of digits).

Terms

    a(0) =1a(1) =3a(2) =6a(3) =15a(4) =28a(5) =55a(6) =66a(7) =91a(8) =105a(9) =120a(10) =153a(11) =171a(12) =210a(13) =231a(14) =276a(15) =300a(16) =351a(17) =378a(18) =435a(19) =465a(20) =528a(21) =561a(22) =630a(23) =666a(24) =741a(25) =780a(26) =861a(27) =903a(28) =990a(29) =1128

External references