Number of (w,x,y,z) with all terms in {1,...,n} and w^2<=x^2+y^2+z^2.

Terms

a(0) =0a(1) =1a(2) =15a(3) =76a(4) =234a(5) =565a(6) =1161a(7) =2145a(8) =3644a(9) =5825a(10) =8854a(11) =12940a(12) =18300a(13) =25173a(14) =33814a(15) =44524a(16) =57587a(17) =73346a(18) =92127a(19) =114312a(20) =140272a(21) =170421a(22) =205198a(23) =245043a(24) =290413a(25) =341832a(26) =399774a(27) =464801a(28) =537425a(29) =618289