Number of even digits necessary to write all positive n-digit integers.

A358439

Number of even digits necessary to write all positive n-digit integers.

Terms

    a(0) =4a(1) =85a(2) =1300a(3) =17500a(4) =220000a(5) =2650000a(6) =31000000a(7) =355000000a(8) =4000000000a(9) =44500000000a(10) =490000000000

External references