a(n) = exp(-1/5) * Sum_{k>=0} (5*k - 1)^n / (5^k * k!).

A337041

a(n) = exp(-1/5) * Sum_{k>=0} (5*k - 1)^n / (5^k * k!).

Terms

    a(0) =1a(1) =0a(2) =5a(3) =25a(4) =200a(5) =1875a(6) =20625a(7) =256250a(8) =3534375a(9) =53515625a(10) =881468750a(11) =15667578125a(12) =298478828125

External references