Number of distinct squares (of any orientation) whose vertices are points of the cross of side n.

Terms

a(0) =1a(1) =21a(2) =115a(3) =372a(4) =919a(5) =1917a(6) =3565a(7) =6096a(8) =9781a(9) =14925a(10) =21871a(11) =30996a(12) =42715a(13) =57477a(14) =75769a(15) =98112a(16) =125065a(17) =157221a(18) =195211a(19) =239700a(20) =291391a(21) =351021a(22) =419365a(23) =497232a(24) =585469a(25) =684957a(26) =796615a(27) =921396a(28) =1060291a(29) =1214325