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A173720 Sum_{ 4 <= c <= A113646(n) } (n mod c), where c runs over all composites A002808. 1

%I

%S 1,2,3,0,6,2,11,2,5,9,25,9,28,21,28,24,50,27,56,33,44,56,92,52,66,81,

%T 88,87,134,92,142,102,122,143,165,139,200,187,212,196,264,209,280,239,

%U 244,274,352,266,298,296,330,335,424,347,384,368,407,447,547,432,535,516,529,513,558

%N Sum_{ 4 <= c <= A113646(n) } (n mod c), where c runs over all composites A002808.

%p A173720 := proc(n) a := 0 ; for i from 1 do c := A002808(i) ; a := a + (n mod c) ; if c >= n then return a; end if; end do: end proc:

%p seq(A173720(n),n=1..80) ; # _R. J. Mathar_, Nov 26 2010

%Y Cf. A002808, A113646.

%K nonn,easy

%O 1,2

%A _Juri-Stepan Gerasimov_, Nov 26 2010

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Last modified June 20 18:28 EDT 2021. Contains 345199 sequences. (Running on oeis4.)