Number of n-letter strings over a ten letter alphabet where no letter appears exactly three times.

A272501

Number of n-letter strings over a ten letter alphabet where no letter appears exactly three times.

Terms

    a(0) =1a(1) =10a(2) =100a(3) =990a(4) =9640a(5) =91900a(6) =855100a(7) =7754050a(8) =68545360a(9) =592095160a(10) =5020469200a(11) =42054532750a(12) =350538754600

External references