A290397 Least number of nonprime squarefree numbers (A000469) that add up to n.

1, 2, 3, 4, 5, 1, 2, 3, 4, 1, 2, 2, 3, 1, 1, 2, 3, 3, 4, 2, 1, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 1, 1, 2, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 1, 1, 2, 2, 2, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 2, 2, 1, 1, 2, 2, 2, 1, 2, 2, 1, 1, 1, 2

Offset

1,2

Comments

It is conjectured that a(n) <= 5.

Links

Table of n, a(n) for n=1..88.

Example

a(6) = 1 because 6 is already nonprime squarefree number.
a(7) = 2 because 7 = 6 + 1 is a partition of 7 into 2 nonprime squarefree parts and there is no such partition with fewer terms.

Crossrefs

Cf. A000469, A051034, A225926, A239508, A290136.

Sequence in context: A338863 A280502 A276757 * A322425 A053841 A010884

Adjacent sequences: A290394 A290395 A290396 * A290398 A290399 A290400

Keyword

nonn

Author

Ilya Gutkovskiy, Jul 29 2017

Status

approved