A145119 a(n) = Product_{k=1..n-1} (ceiling(n/k) - ceiling(n/k) mod 2).

1, 2, 4, 16, 32, 96, 384, 1024, 2048, 10240, 30720, 73728, 294912, 688128, 1835008, 12582912, 25165824, 56623104, 283115520, 629145600, 1887436800, 11072962560, 26575110144, 57982058496, 231928233984, 753766760448, 1758789107712

Offset: 1

Author

Reikku Kulon, Oct 02 2008

Keywords

• easy
• nonn

Comments

Bounded by A010786 and A131385.

Each term has many more factors of two than any other prime factor.

Crossrefs

Cf. A010786, A131385, A131387.

Programs

PARI

a(n) = prod(k=1, n-1, ceil(n/k) - ceil(n/k) % 2); \\ Michel Marcus, Nov 17 2019