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 A062953 Multiplicative with a(p^e) = -p. 5
 1, -2, -3, -2, -5, 6, -7, -2, -3, 10, -11, 6, -13, 14, 15, -2, -17, 6, -19, 10, 21, 22, -23, 6, -5, 26, -3, 14, -29, -30, -31, -2, 33, 34, 35, 6, -37, 38, 39, 10, -41, -42, -43, 22, 15, 46, -47, 6, -7, 10, 51, 26, -53, 6, 55, 14, 57, 58, -59, -30, -61, 62, 21, -2, 65, -66, -67, 34, 69, -70, -71, 6, -73, 74, 15, 38, 77, -78, -79 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Except for first term, row products of A142971. - Mats Granvik and Gary W. Adamson, Jul 15 2008 Dirichlet inverse of A003968. - Werner Schulte, Oct 25 2018 LINKS Ivan Neretin, Table of n, a(n) for n = 1..10000 FORMULA a(n) = Sum_{ d divides n } mu(d)*sigma(d) = sum_{d|n} A063441(d). From Enrique Pérez Herrero, Aug 24 2010: (Start) a(n) = Sum_{d|n} mu(d)*psi(d), where psi is A001615. a(n) = rad(n)*(-1)^omega(n)=A007947(n)*(-1)^A001221(n). (End) G.f.: Sum_{k>=1} mu(k)*sigma(k)*x^k/(1 - x^k). - Ilya Gutkovskiy, Feb 19 2017 MAPLE with(numtheory): seq(coeff(series(add(mobius(k)*sigma(k)*x^k/(1-x^k), k=1..n), x, n+1), x, n), n = 1 .. 80); # Muniru A Asiru, Oct 26 2018 MATHEMATICA A062953[n_]:=DivisorSum[n, MoebiusMu[ # ]*DivisorSigma[1, # ]&] (* Enrique Pérez Herrero, Aug 24 2010 *) PROG (PARI) a(n) = sumdiv(n, d, moebius(d)*sigma(d)); \\ Michel Marcus, Feb 19 2017 CROSSREFS Apart from signs, essentially same as A007947. Cf. A142971, A003968. Sequence in context: A088835 A007947 A015053 * A015052 A053166 A166140 Adjacent sequences:  A062950 A062951 A062952 * A062954 A062955 A062956 KEYWORD mult,sign AUTHOR Vladeta Jovovic, Jul 21 2001 STATUS approved

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Last modified September 26 03:58 EDT 2020. Contains 337346 sequences. (Running on oeis4.)