Number of integer solutions to (x_1)^2 + (x_2)^2 + ... + (x_7)^2 <= n.

Terms

a(0) =1a(1) =15a(2) =99a(3) =379a(4) =953a(5) =1793a(6) =3081a(7) =5449a(8) =8893a(9) =12435a(10) =16859a(11) =24419a(12) =33659a(13) =42115a(14) =53203a(15) =69779a(16) =88273a(17) =106081a(18) =125821a(19) =153541a(20) =187981a(21) =217437a(22) =248741a(23) =298469a(24) =351277a(25) =394691a(26) =446939a(27) =515259a(28) =589307a(29) =657683