A013934 Nonsquarefree numbers k such that the sum of all nonsquarefree numbers <= k is nonsquarefree.

4, 8, 16, 25, 44, 45, 48, 63, 64, 68, 72, 76, 81, 84, 88, 92, 98, 104, 108, 116, 117, 120, 126, 128, 132, 150, 152, 156, 164, 169, 175, 184, 196, 198, 204, 207, 208, 212, 216, 220, 224, 232, 234, 243, 244, 245, 256, 261, 264, 268, 270, 279, 280, 284, 288, 297, 300, 304

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A013929(A013933(n)). - Amiram Eldar, Feb 11 2021

Mathematica

nsf = Select[Range[400], ! SquareFreeQ[#] &]; nsf[[Position[Accumulate@nsf, _?(!SquareFreeQ[#] &)] // Flatten]] (* Amiram Eldar, Feb 11 2021 *)

Crossrefs

Cf. A013929, A013933, A013935.

Sequence in context: A193452 A003451 A277029 * A167189 A050470 A138501

Adjacent sequences: A013931 A013932 A013933 * A013935 A013936 A013937

Keyword

nonn

Author

Henri Lifchitz

Extensions

More terms from David W. Wilson

Status

approved