185200

Appears in sequences

• a(n) = AlexanderPolynomial[n] defined as Det[Transpose[S]-n S] where S is Kronecker Product of two 2 X 2 Seifert matrices {{-1, 1}, {0, -1}} [X] {{-1, 1}, {0, -1}} = {{1, -1, -1, 1}, {0, 1, 0, -1}, {0, 0, 1, -1}, {0, 0, 0, 1}}.at n=21A138849
• Number of ways to place 2 nonattacking bishops on an n X n board.at n=24A172123
• Number of regions formed by drawing the lines connecting any two of the 2*(n+2) perimeter points of a 3 X (n+1) rectangular grid of points (or equally, a 2 X n grid of squares).at n=29A331766
• Number of subsets of {1..n} containing n but not containing the sum of any two distinct elements.at n=29A364755