A282380 Number of ways to write n as a sum of two unordered nonsquarefree numbers.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 2, 1, 1, 0, 2, 1, 1, 0, 3, 1, 1, 1, 3, 2, 1, 1, 4, 2, 2, 1, 6, 2, 1, 1, 5, 2, 1, 2, 5, 3, 1, 1, 6, 3, 2, 1, 7, 4, 4, 1, 7, 4, 4, 2, 7, 4, 3, 3, 8, 4, 3, 3, 9, 4, 4, 2, 12, 4, 4, 3, 10, 5, 3, 4, 10, 6, 3, 3, 11, 5, 3, 3, 12, 5, 6, 3, 11, 6, 5, 4, 12, 5, 5, 7, 14, 5, 6, 5, 14, 5, 6

Offset

1,16

Links

Altug Alkan, Table of n, a(n) for n = 1..10000

Example

a(16) = 2 because 16 = 4 + 12 and 16 = 8 + 8 are only corresponding solutions.

Prog

(PARI) a(n) = sum(k=1, n\2, !issquarefree(k) && !issquarefree(n-k));

Crossrefs

Cf. A013929, A071068.

Sequence in context: A219052 A060826 A078134 * A083661 A029369 A255315

Adjacent sequences: A282377 A282378 A282379 * A282381 A282382 A282383

Keyword

nonn

Author

Altug Alkan, Feb 13 2017

Status

approved