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

Terms

a(0) =1a(1) =5a(2) =53a(3) =115a(4) =3163a(5) =3263a(6) =170687a(7) =352399a(8) =1096397a(9) =223513a(10) =28103473a(11) =28459213a(12) =4963286677a(13) =5029541437a(14) =25532475569a(15) =51741301813