Largest n-digit number k with only odd digits such that the k-th triangular number also has only odd digits.

A355277

Largest n-digit number k with only odd digits such that the k-th triangular number also has only odd digits.

Terms

    a(0) =5a(1) =17a(2) =177a(3) =5573a(4) =79137a(5) =791377a(6) =7913777a(7) =79971937a(8) =557335733a(9) =5995957537a(10) =59995599137a(11) =599591791137

External references