A123732 - OEIS

%I #13 Aug 26 2022 05:25:51

%S 1,4,6,4,0,0,3,5,4,3,6,0,3,1,8,2,0,2,5,9,3,8,4,2,4,8,9,4,3,4,5,4,2,7,

%T 0,8,9,8,3,9,6,1,9,9,5,7,9,4,9,4,5,6,7,6,8,3,0,5,3,5,6,4,5,9,0,5,4,7,

%U 2,8,9,5,4,8,5,0,5,8,5,3,9,9,7,8,8,4,9,2,3,6,7,4,5,1,2,6,2,6,6,0,6,2,3,3,3

%N Decimal expansion of Sum_{m>=1} (-1)Sigma(m)/m^3.

%C The sum over (-1)Sigma(m)/m^2 is divergent.

%F Equals Sum_{m>=1} A049060(m)/m^3.

%F Equals Product_{p prime} (1 + (p^3-p^2+1)/((p-1)^2*(p+1)*(p^2+p+1))). - _Amiram Eldar_, Aug 26 2022

%e 1.46400354360318202593842489434542708983961995794945...

%o (PARI) prodeulerrat(1 + (p^3-p^2+1)/((p-1)^2*(p+1)*(p^2+p+1))) \\ _Amiram Eldar_, Aug 26 2022

%Y Cf. A049060, A123733, A123734, A183699.

%K nonn,cons

%O 1,2

%A _Yasutoshi Kohmoto_, Nov 18 2006

%E 40 more digits from _R. J. Mathar_, Dec 19 2010

%E More terms from _Amiram Eldar_, Aug 26 2022