A355243 a(n) is the largest integer value of Product_{k=1..n} (2 + 1/t_k) with integers t_k > 1.

5, 11, 25, 55, 125, 277, 637, 1421, 3237, 7553, 16807, 38661, 90209, 208397

Offset: 2

Author

Hugo Pfoertner and Markus Sigg, Jul 16 2022

Keywords

• nonn
• hard
• more

Examples

			a(2) = 5 = (2 + 1/3) * (2 + 1/7),
a(3) = 11 = (2 + 1/3) * (2 + 1/5) * (2+1/7) = (2 + 1/3)^2 * (2 + 1/49),
a(7) = 277 = (2 + 1/3)^5 * ( 2 + 1/405) * (2 + 1/13630477).
		

Crossrefs

A355626 gives more information.

A355630 same problem with factors (3 + 1/t_k).

Programs

PARI

\\ See link in A355626