OFFSET
1,11
MATHEMATICA
a[1] = a[2] = a[3] = 1; a[n_] := a[n] = Sum[MoebiusMu[(n - 3)/d] a[d], {d, Divisors[n - 3]}]; Table[a[n], {n, 75}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Apr 07 2021
STATUS
approved