For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = sum of the values of |v|.

Terms

a(0) =1a(1) =3a(2) =7a(3) =12a(4) =22a(5) =30a(6) =49a(7) =66a(8) =91a(9) =114a(10) =160a(11) =189a(12) =253a(13) =300a(14) =355a(15) =420a(16) =529a(17) =597a(18) =733a(19) =819a(20) =931a(21) =1053a(22) =1252a(23) =1365a(24) =1564a(25) =1737a(26) =1945a(27) =2121a(28) =2437a(29) =2604