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A330324
a(n) = Sum_{i=1..n} Moebius(i)*Moebius(i+1), where Moebius(n) = A008683(n).
2
-1, 0, 0, 0, -1, -2, -2, -2, -2, -3, -3, -3, -4, -3, -3, -3, -3, -3, -3, -3, -2, -3, -3, -3, -3, -3, -3, -3, -2, -1, -1, -1, 0, 1, 1, 1, 0, 1, 1, 1, 2, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, -1, 0, 0, 0, 0, -1, -1, -1, 0, 1, 1
OFFSET
1,6
LINKS
MAPLE
a:= proc(n) option remember; `if`(n<1, 0,
a(n-1)+numtheory[mobius](n*(n+1)))
end:
seq(a(n), n=1..100); # Alois P. Heinz, Apr 17 2021
MATHEMATICA
Accumulate @ Table[MoebiusMu[n] * MoebiusMu[n+1], {n, 1, 100}] (* Amiram Eldar, Jul 26 2022 *)
PROG
(PARI) a(n) = sum(i=1, n, moebius(i*(i+1))); \\ Michel Marcus, Jul 26 2022
CROSSREFS
Partial sums of A330323.
Cf. A008683.
Sequence in context: A054893 A090617 A053693 * A341132 A291309 A280472
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Dec 12 2019
STATUS
approved