Sum of lcm(gcd(i,j), gcd(k,l)) for i,j,k,l in range [1..n].

Terms

a(0) =1a(1) =23a(2) =136a(3) =516a(4) =1289a(5) =3271a(6) =5908a(7) =11084a(8) =18833a(9) =31503a(10) =44072a(11) =71156a(12) =93681a(13) =133095a(14) =190052a(15) =256468a(16) =311909a(17) =421619a(18) =501412a(19) =664112a(20) =847013a(21) =1035763a(22) =1186208a(23) =1515000a(24) =1790625a(25) =2114575a(26) =2502268a(27) =3028600a(28) =3354613a(29) =4109163