Let P(A) be 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 intersecting but for which x is not a subset of y and y is not a subset of x, or 1) x = y.
A134019
Let P(A) be 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 intersecting but for which x is not a subset of y and y is not a subset of x, or 1) x = y.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =11a(4) =46a(5) =227a(6) =1114a(7) =5231a(8) =23566a(9) =102827a(10) =438274a(11) =1836551a(12) =7601686a(13) =31183427a(14) =127084234a(15) =515429471a(16) =2083077406a(17) =8396552027a(18) =33779262994a(19) =135696871991a(20) =544528258726
External references
- oeis: A134019