OFFSET
0,4
COMMENTS
Equals row sums of triangle A144029.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..2000
FORMULA
a(4) = -7 = (0, -3, -2, 1) dot (1, 1, -1, -6); where (0, -3, -2, 1) = the first 4 terms of n*mu(n) reversed. (1, 1, -1, -6) = the first 4 terms of the INVERT recursion operation.
MAPLE
a:= proc(n) option remember; `if`(n=0, 1,
add(a(n-i)*i*numtheory[mobius](i), i=1..n))
end:
seq(a(n), n=0..40); # Alois P. Heinz, Sep 22 2017
MATHEMATICA
a[n_] := a[n] = If[n == 0, 1, Sum[a[n-i]*i*MoebiusMu[i], {i, 1, n}]];
Table[a[n], {n, 0, 40}] (* Jean-François Alcover, May 18 2018, translated from Maple *)
CROSSREFS
KEYWORD
sign
AUTHOR
Gary W. Adamson, Sep 07 2008
EXTENSIONS
Corrected from a(9) onwards by R. J. Mathar, Jan 27 2011
a(0)=1 prepended by Alois P. Heinz, Sep 22 2017
STATUS
approved