Number of ordered 5-tuples of integers from [ 2,n ] with no common factors among quadruples.

Terms

a(0) =0a(1) =2a(2) =7a(3) =32a(4) =56a(5) =156a(6) =266a(7) =498a(8) =750a(9) =1366a(10) =1846a(11) =3037a(12) =4086a(13) =5794a(14) =7615a(15) =11061a(16) =13597a(17) =18938a(18) =23262a(19) =30012a(20) =36537a(21) =47920a(22) =56072a(23) =71259a(24) =84110a(25) =102874a(26) =119889a(27) =148382a(28) =167710a(29) =204747