Number of ordered quadruples of distinct pairwise coprime positive integers with largest element n; also first differences of A015623.

A185348

Number of ordered quadruples of distinct pairwise coprime positive integers with largest element n; also first differences of A015623.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =0a(6) =8a(7) =4a(8) =10a(9) =2a(10) =42a(11) =4a(12) =79a(13) =16a(14) =25a(15) =36a(16) =183a(17) =20a(18) =277a(19) =50a(20) =100a(21) =70a(22) =491a(23) =56a(24) =399a(25) =139a(26) =340a(27) =146a(28) =1016a(29) =56

External references