Number of integer grid points on the circle around (0,0) with radius A088959(n).

Terms

a(0) =4a(1) =12a(2) =20a(3) =36a(4) =60a(5) =108a(6) =180a(7) =252a(8) =324a(9) =540a(10) =756a(11) =972a(12) =1620a(13) =2268a(14) =2916a(15) =4860a(16) =6804a(17) =8748a(18) =14580a(19) =20412a(20) =26244a(21) =43740a(22) =61236a(23) =72900a(24) =78732a(25) =102060a(26) =131220a(27) =183708a(28) =218700a(29) =236196