Number of Integer solutions to w^2 + x^2 + y^2 + z^2 < n^2; number of lattice points inside a 4-sphere of radius n.

A319617

Number of Integer solutions to w^2 + x^2 + y^2 + z^2 < n^2; number of lattice points inside a 4-sphere of radius n.

Terms

    a(0) =0a(1) =1a(2) =65a(3) =321a(4) =1257a(5) =2873a(6) =6265a(7) =11377a(8) =20161a(9) =31665a(10) =48945a(11) =71401a(12) =102041a(13) =139481a(14) =188753a(15) =247329a(16) =323697a(17) =409457a(18) =516121a(19) =640393a(20) =789161a(21) =955793a(22) =1153025a(23) =1376305a(24) =1637929a(25) =1921049a(26) =2252889a(27) =2615673a(28) =3033665a(29) =3483633

External references