Partial alternating sums of the sigma_2 function: a(n) = Sum_{k=1..n} (-1)^(k+1) * sigma_2(k).

Terms

a(0) =1a(1) =-4a(2) =6a(3) =-15a(4) =11a(5) =-39a(6) =11a(7) =-74a(8) =17a(9) =-113a(10) =9a(11) =-201a(12) =-31a(13) =-281a(14) =-21a(15) =-362a(16) =-72a(17) =-527a(18) =-165a(19) =-711a(20) =-211a(21) =-821a(22) =-291a(23) =-1141a(24) =-490a(25) =-1340a(26) =-520a(27) =-1570a(28) =-728a(29) =-2028