Number of (w,x,y,z) with all terms in {0,...,n} and (least gapsize)=1.

Terms

a(0) =0a(1) =2a(2) =22a(3) =92a(4) =246a(5) =520a(6) =950a(7) =1572a(8) =2422a(9) =3536a(10) =4950a(11) =6700a(12) =8822a(13) =11352a(14) =14326a(15) =17780a(16) =21750a(17) =26272a(18) =31382a(19) =37116a(20) =43510a(21) =50600a(22) =58422a(23) =67012a(24) =76406a(25) =86640a(26) =97750a(27) =109772a(28) =122742a(29) =136696