Number of 2n-digit decimal numbers without leading zeros where each digit appears an even number of times.
A303050
Number of 2n-digit decimal numbers without leading zeros where each digit appears an even number of times.
Terms
- a(0) =9a(1) =252a(2) =10944a(3) =617472a(4) =41457024a(5) =3141499392a(6) =259346018304
External references
- oeis: A303050