85280

Appears in sequences

• If X_1, ..., X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 3-subsets of X containing none of X_i, (i=1,...,n).at n=38A130809
• Number of -n..n arrays x(0..3) of 4 elements with sum zero and with zeroth through 3rd differences all nonzero.at n=25A200040
• Number of (n+1)X(2+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically.at n=2A253478
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically.at n=8A253482
• Number of (3+1)X(n+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically.at n=1A253484
• Rectangular array read by downward antidiagonals; row n consists of the numbers m such that n is the denominator of d(k)/d(1) + d(k-1)/d(2) + ... + d(k)/d(1), where d(1),d(2),...,d(k) are the unitary divisors of m.at n=48A305995
• E.g.f. A(x) satisfies A(x) = log( 1 + x * cos(2*A(x)) ).at n=6A380555
• Number of positions of the 8 X 2 variant of the 15-puzzle at a distance of n multi-tile moves from an initial state with the empty square in one of the corners.at n=11A389729