Numbers k such that the k-th triangular number contains only digits {3,7,8}.

A119201

Numbers k such that the k-th triangular number contains only digits {3,7,8}.

Terms

    a(0) =2a(1) =12a(2) =27a(3) =132a(4) =1332a(5) =13332a(6) =132572a(7) =133332a(8) =384132a(9) =1333332a(10) =4215052a(11) =8646772a(12) =13333332a(13) =133333332a(14) =1333333332a(15) =13333333332a(16) =133333333332

External references