112156

Appears in sequences

• Let P(A) denote the power set of an n-element set A. Then a(n) = the number of pairs of elements {x,y} of P(A) for which either 0) x and y are disjoint and for which x is not a subset of y and y is not a subset of x, 1) x and y are disjoint and for which either x is a subset of y or y is a subset of x, or 2) x and y intersect but for which x is not a subset of y and y is not a subset of x.at n=9A133789
• Number of non-collinear triples in a 5 X n rectangular grid.at n=17A334707
• a(n) is the number of binary (0,1) sequences of length n that have at least two ones in each window of eight consecutive symbols.at n=17A335247