A369392 Number of subsets of {2..n} such that the product of the elements plus 1 is a prime.

1, 1, 2, 3, 5, 9, 18, 32, 56, 111, 211, 386, 727, 1374, 2654, 5018, 9346, 17946, 33654, 63754, 120619, 229835, 443058, 834608, 1563645, 2999088, 5843122, 11070802, 21253933, 41347141, 79197559, 153735211, 293761934, 570421574, 1112023166, 2153293449

Offset: 0

Author

Ilya Gutkovskiy, Jan 22 2024

Keywords

• nonn

Examples

			a(5) = 9 subsets: {}, {2}, {4}, {2, 3}, {2, 5}, {3, 4}, {2, 3, 5}, {2, 4, 5} and {3, 4, 5}.
		

Crossrefs

Cf. A000040, A127542.

Extensions

a(22)-a(35) from Alois P. Heinz, Jan 22 2024