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

Terms

a(0) =0a(1) =1a(2) =9a(3) =45a(4) =139a(5) =333a(6) =684a(7) =1258a(8) =2133a(9) =3402a(10) =5167a(11) =7542a(12) =10656a(13) =14647a(14) =19665a(15) =25875a(16) =33451a(17) =42579a(18) =53460a(19) =66304a(20) =81333a(21) =98784a(22) =118903a(23) =141948a(24) =168192a(25) =197917a(26) =231417a(27) =269001a(28) =310987a(29) =357705