Numbers k such that the k-th triangular number contains only digits {3,5,6}.

Terms

a(0) =2a(1) =3a(2) =8a(3) =10a(4) =11a(5) =36a(6) =85a(7) =103a(8) =105a(9) =114a(10) =816a(11) =2696a(12) =3363a(13) =8430a(14) =10617a(15) =10645a(16) =11257a(17) =36211a(18) =327210a(19) =333657a(20) =1032989a(21) =1054071a(22) =3647836a(23) =33336636a(24) =265918617a(25) =36148757471a(26) =259095941942a(27) =326605681382