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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.
2
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
3,1
FORMULA
a(n) = (n^12 - 15*n^10 + 55*n^8 + 75*n^6)/720 + O(n^4).
CROSSREFS
Sequence in context: A232913 A209542 A028461 * A221608 A283922 A224100
KEYWORD
nonn
AUTHOR
Heinrich Ludwig, May 09 2014
EXTENSIONS
a(12)-a(14) from Heinrich Ludwig, Dec 01 2016
a(15)-a(30) from Max Alekseyev, Feb 19 2024
STATUS
approved