Quadruples (a,b,c,d) of the form ( n*(n^3-1), n^3-1, 2*n^3+1, n*(n^3+2) ).

Terms

a(0) =0a(1) =0a(2) =3a(3) =3a(4) =14a(5) =7a(6) =17a(7) =20a(8) =78a(9) =26a(10) =55a(11) =87a(12) =252a(13) =63a(14) =129a(15) =264a(16) =620a(17) =124a(18) =251a(19) =635a(20) =1290a(21) =215a(22) =433a(23) =1308a(24) =2394a(25) =342a(26) =687a(27) =2415a(28) =4088a(29) =511