A046857 a(n) = (2^n)!/(n!^2).

2, 6, 1120, 36324288000, 18272974787062050706056806400000, 244766458691906180755079840538505942906762183978675139272380197483053056000000000000

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• C. S. Lorens, Invertible Boolean functions, IEEE Trans. Electron. Computers, EC-13 (1964), 529-541.
• C. S. Lorens, Invertible Boolean functions, IEEE Trans. Electron. Computers, EC-13 (1964), 529-541. [Annotated scan of page 530 only]