A329472 Partial sums of numbers that are not squarefree.

4, 12, 21, 33, 49, 67, 87, 111, 136, 163, 191, 223, 259, 299, 343, 388, 436, 485, 535, 587, 641, 697, 757, 820, 884, 952, 1024, 1099, 1175, 1255, 1336, 1420, 1508, 1598, 1690, 1786, 1884, 1983, 2083, 2187, 2295, 2407, 2523, 2640, 2760, 2881, 3005, 3130, 3256

Offset

1,1

Links

Metin Sariyar, Table of n, a(n) for n = 1..16000

Formula

a(n) ~ (Pi^2/(2*Pi^2 - 12)) * n^2. - Amiram Eldar, Oct 21 2020

Example

49 is a term because 4, 8, 9, 12, 16 are the first five nonsquarefree numbers and 4 + 8 + 9 + 12 + 16 = 49.

Mathematica

Accumulate[Select[Range[1000], !SquareFreeQ[#]&]]

Crossrefs

Partial sums of A013929.

Cf. A005117, A173143.

Sequence in context: A270795 A191260 A047965 * A301071 A038430 A301262

Adjacent sequences: A329469 A329470 A329471 * A329473 A329474 A329475

Keyword

nonn,easy

Author

Metin Sariyar, Nov 13 2019

Status

approved