A369391 Number of nonempty subsets of {1..n} whose elements have a square average.

1, 1, 1, 2, 4, 10, 20, 26, 31, 35, 41, 63, 143, 399, 1083, 2554, 5078, 8596, 12772, 17222, 21792, 27126, 36538, 62530, 146701, 412191, 1178071, 3156949, 7703823, 16992539, 33946851, 61840501, 103674983, 161604395, 236759149, 330078718, 446073360, 606337592

Offset: 1

Author

Ilya Gutkovskiy, Jan 22 2024

Keywords

• nonn

Examples

			a(5) = 4 subsets: {1}, {4}, {3, 5} and {3, 4, 5}.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A051293, A126024, A309160, A339454, A357355.

Extensions

a(24)-a(38) from Alois P. Heinz, Jan 22 2024