a(n) = 9^n - 8*8^n + 28*7^n - 56*6^n + 70*5^n - 56*4^n + 28*3^n - 8*2^n + 1.

A228911

a(n) = 9^n - 8*8^n + 28*7^n - 56*6^n + 70*5^n - 56*4^n + 28*3^n - 8*2^n + 1.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =40320a(9) =1814400a(10) =46569600a(11) =898128000a(12) =14495120640a(13) =207048441600

External references