Number of (w,x,y,z) with all terms in {1,...,n} and w >= (geometric mean of x,y,z).

Terms

a(0) =0a(1) =1a(2) =9a(3) =45a(4) =145a(5) =351a(6) =729a(7) =1345a(8) =2307a(9) =3702a(10) =5650a(11) =8271a(12) =11736a(13) =16174a(14) =21774a(15) =28719a(16) =37210a(17) =47457a(18) =59703a(19) =74170a(20) =91116a(21) =110796a(22) =133498a(23) =159525a(24) =189246a(25) =222880a(26) =260835a(27) =303465a(28) =351103a(29) =404109