Number of 5-tuples of different integers from [ 1,n ] with no common factors among quadruples.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =6a(6) =21a(7) =52a(8) =121a(9) =226a(10) =431a(11) =688a(12) =1167a(13) =1726a(14) =2651a(15) =3696a(16) =5441a(17) =7140a(18) =10059a(19) =12941a(20) =17287a(21) =21710a(22) =28659a(23) =34724a(24) =44705a(25) =53942a(26) =67131a(27) =79828a(28) =99171a(29) =114846