1,2

Differs from A085263 where the square cannot be zero.

Table of n, a(n) for n=1..90.

Jorge Urroz, Every integer can be written as a square plus a squarefree, arXiv:2010.15580 [math.NT], 2020.

(PARI) a(n) = sum(k=0, n, issquare(k) * issquarefree(n-k));

Cf. A000290, A005117, A085263 (with a positive square).

Sequence in context: A070680 A054711 A241424 * A294232 A331254 A193738

Adjacent sequences: A334668 A334669 A334670 * A334672 A334673 A334674

nonn

Michel Marcus, Oct 31 2020

approved