OFFSET
1,4
EXAMPLE
For n = 4, A007955(n) = b(n): a(4) = b(1)*mu(4) + b(2)*mu(3) + b(3)* mu(2) + b(4)*mu(1) = 1*0 + 2*(-1) + 3*(-1) + 8*1 = 3.
MATHEMATICA
a[n_] := Sum[k^(DivisorSigma[0, k]/2) * MoebiusMu[n-k+1], {k, 1, n}]; Array[a, 50] (* Amiram Eldar, Aug 06 2024 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Jaroslav Krizek, Apr 02 2010
EXTENSIONS
More terms from Amiram Eldar, Aug 06 2024
STATUS
approved