Numerator of Sum_{k=1..n} (-1)^(k+1)/k^2.

Terms

a(0) =1a(1) =3a(2) =31a(3) =115a(4) =3019a(5) =973a(6) =48877a(7) =191833a(8) =5257891a(9) =5194387a(10) =634871227a(11) =629535127a(12) =107159834863a(13) =106497287263a(14) =107074439839a(15) =426268707331