A240446 Numbers of ways to place six indistinguishable points on an n X n square grid so that no four of them are vertices of a square of any orientation.
32, 6726, 166702, 1895938, 13790212, 74380406, 322961410, 1188292304, 3835115230, 11126671552, 29549197210, 72828900336, 168386628278, 368360769558, 767733010896, 1533170797506, 2947620125778, 5477517677094, 9871827636572, 17305042166112, 29579923394356, 49410229230976, 80809088567212, 129615220384928, 204196987161028, 316383511891814, 482682961875178, 725860819178050
Offset: 3
Keywords
Formula
a(n) = (n^12 - 15*n^10 + 55*n^8 + 75*n^6)/720 + O(n^4).
Extensions
a(12)-a(14) from Heinrich Ludwig, Dec 01 2016
a(15)-a(30) from Max Alekseyev, Feb 19 2024