Numbers k such that the k-th triangular number contains only digits {0,7,8}.

A119094

Numbers k such that the k-th triangular number contains only digits {0,7,8}.

Terms

    a(0) =12a(1) =39a(2) =132a(3) =1332a(4) =13332a(5) =41732a(6) =118387a(7) =126560a(8) =133332a(9) =1241612a(10) =1333332a(11) =11905535a(12) =13333332a(13) =124970227a(14) =133333332a(15) =1333333332a(16) =11906972812a(17) =13333333332a(18) =37418660507a(19) =37626774267a(20) =42163256012a(21) =133333333332

External references