OFFSET
1,5
LINKS
Indranil Ghosh, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = Sum_{k=1..n} mu(k)*(n-k+1) where mu=A008683, the Moebius function. - Reinhard Zumkeller, Nov 06 2006
G.f.: (1/(1 - x)^2)*Sum_{k>=1} mu(k)*x^k. - Ilya Gutkovskiy, Mar 11 2018
MATHEMATICA
Table[Sum[MoebiusMu[k] (n - k + 1), {k, 1, n}], {n , 1, 56}] (* Indranil Ghosh, Mar 16 2017 *)
PROG
(PARI) for(n=1, 56, print1(sum(k=1, n, moebius(k) * (n - k + 1)), ", ")) \\ Indranil Ghosh, Mar 16 2017
CROSSREFS
KEYWORD
sign
AUTHOR
Jon Perry, Mar 04 2004
EXTENSIONS
More terms from Reinhard Zumkeller, Nov 06 2006
STATUS
approved