Triangular numbers composed of digits {0,5,6}.

Terms

a(0) =6a(1) =55a(2) =66a(3) =666a(4) =5050a(5) =5565a(6) =6555a(7) =66066a(8) =500500a(9) =600060a(10) =605550a(11) =5656566a(12) =50005000a(13) =60505500a(14) =5000050000a(15) =6050055000a(16) =500000500000a(17) =605000550000