Number of nonnegative solutions to x^2 + y^2 + z^2 <= n.

Terms

a(0) =1a(1) =4a(2) =7a(3) =8a(4) =11a(5) =17a(6) =20a(7) =20a(8) =23a(9) =29a(10) =35a(11) =38a(12) =39a(13) =45a(14) =51a(15) =51a(16) =54a(17) =63a(18) =69a(19) =72a(20) =78a(21) =84a(22) =87a(23) =87a(24) =90a(25) =99a(26) =111a(27) =115a(28) =115a(29) =127