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

Terms

a(0) =0a(1) =0a(2) =2a(3) =16a(4) =74a(5) =230a(6) =562a(7) =1172a(8) =2186a(9) =3754a(10) =6050a(11) =9272a(12) =13642a(13) =19406a(14) =26834a(15) =36220a(16) =47882a(17) =62162a(18) =79426a(19) =100064a(20) =124490a(21) =153142a(22) =186482a(23) =224996a(24) =269194a(25) =319610a(26) =376802a(27) =441352a(28) =513866a(29) =594974