A352601 a(n) = RisingFactorial(2*n, n) = A124320(2*n, n).

1, 2, 20, 336, 7920, 240240, 8910720, 390700800, 19769460480, 1133836704000, 72684900288000, 5150244363264000, 399703747322880000, 33719008124158156800, 3072176295756632064000, 300649528529562820608000, 31451820032947491201024000, 3502589049123697883750400000

Offset: 0

Author

Peter Luschny, Mar 22 2022

Keywords

• nonn

Crossrefs

Cf. A124320.

Programs

Mathematica

Table[Pochhammer[2*n, n], {n, 0, 17}] (* Amiram Eldar, Mar 22 2022 *)

Python

from sympy import rf
def A352601(n): return rf(2*n,n) # Chai Wah Wu, Mar 22 2022

Sage

def a(n): return rising_factorial(2*n, n)
print([a(n) for n in range(18)])

Formula

a(n) ~ 3^(3*n - 1/2) * n^n / (2^(2*n - 1/2) * exp(n)). - Vaclav Kotesovec, Aug 02 2024