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

Terms

a(0) =0a(1) =0a(2) =7a(3) =45a(4) =150a(5) =373a(6) =768a(7) =1437a(8) =2479a(9) =4002a(10) =6120a(11) =9010a(12) =12786a(13) =17661a(14) =23821a(15) =31464a(16) =40809a(17) =52102a(18) =65577a(19) =81531a(20) =100201a(21) =121911a(22) =146979a(23) =175717a(24) =208434a(25) =245550a(26) =287401a(27) =334380a(28) =386877a(29) =445366