Group the natural numbers so that the n-th group contains n numbers whose concatenation is divisible by n: (1), (2, 4), (3, 5, 7), (6, 8, 9, 12), (10, 11, 13, 14, 15), (16, 17, 18, 19, 20, 24), ... Sequence gives numbers formed by the concatenation.
A075621
Group the natural numbers so that the n-th group contains n numbers whose concatenation is divisible by n: (1), (2, 4), (3, 5, 7), (6, 8, 9, 12), (10, 11, 13, 14, 15), (16, 17, 18, 19, 20, 24), ... Sequence gives numbers formed by the concatenation.
Terms
- a(0) =1a(1) =24a(2) =357a(3) =68912a(4) =1011131415a(5) =161718192024
External references
- oeis: A075621