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a(n) is the largest integer that can be written as Product_{i = 1..n} (3 + 1/t_i) with integers t_i >= 2.
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%I #12 Aug 02 2022 09:19:12

%S 11,37,121,413,1442,5047,16807,58457,204085,709667,2483663,8068753,

%T 30415033

%N a(n) is the largest integer that can be written as Product_{i = 1..n} (3 + 1/t_i) with integers t_i >= 2.

%C Obviously 3^n < a(n) < 3.5^n.

%e 11 = (3 + 1/2) * (3 + 1/7) is the largest integer p that can be written as p = (3 + 1/t_1) * (3 + 1/t_2) with integers t_1,t_2 >= 2 because any such integer p is smaller than 3.5^2 = 12.25 and there is no such representation for p = 12. Hence, a(2) = 11.

%o (PARI) See A355626.

%Y Cf. A355626, A355627, A355628, A355629, A355631.

%K more,nonn

%O 2,1

%A _Markus Sigg_, Jul 15 2022