Number of ordered triples (i,j,k) with |i|,|j|,|k|,|i*j*k| <= n and gcd(i,j,k) <= 1.

Terms

a(0) =1a(1) =27a(2) =75a(3) =147a(4) =243a(5) =363a(6) =483a(7) =651a(8) =819a(9) =1011a(10) =1179a(11) =1443a(12) =1683a(13) =1995a(14) =2211a(15) =2475a(16) =2763a(17) =3171a(18) =3459a(19) =3915a(20) =4251a(21) =4611a(22) =4923a(23) =5475a(24) =5883a(25) =6411a(26) =6771a(27) =7275a(28) =7707a(29) =8403