a(n) is the number of pairs x <= y of n-digit numbers such that the number of distinct digits in their product is less than in their concatenation.

A370678

a(n) is the number of pairs x <= y of n-digit numbers such that the number of distinct digits in their product is less than in their concatenation.

Terms

    a(0) =10a(1) =1395a(2) =147718a(3) =15187437a(4) =1530456465a(5) =152653821364

External references