1,9

a(n) + A073311(n) = A000010(n).

Table of n, a(n) for n=1..91.

n=15, there are A000010(15)=8 residues: 1, 2, 4=2^2, 7, 8=2^3, 11, 13 and 14; two of them are not squarefree: 4 and 8, therefore a(15)=2.

Cf. A073311, A013929, A000010, A048864, A048865.

Sequence in context: A262677 A307742 A297109 * A166514 A246024 A278529

Adjacent sequences: A073309 A073310 A073311 * A073313 A073314 A073315

nonn

Reinhard Zumkeller, Jul 25 2002

approved