Factorable subsets: the number of proper subsets S of {1,2,...,n} that can be expressed in the form S=A*B, where S is defined to be the set {a(i)*b(j)| a(i) in A, b(j) in B}.
A068594
Factorable subsets: the number of proper subsets S of {1,2,...,n} that can be expressed in the form S=A*B, where S is defined to be the set {a(i)*b(j)| a(i) in A, b(j) in B}.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =3a(4) =3a(5) =11a(6) =11a(7) =23a(8) =33a(9) =63a(10) =63a(11) =137a(12) =137a(13) =257a(14) =320a(15) =535a(16) =535a(17) =1071a(18) =1071a(19) =2031a(20) =2281a(21) =4073a(22) =4073a(23) =7783a(24) =7908a(25) =14692a(26) =15455a(27) =29277a(28) =29277a(29) =58419
External references
- oeis: A068594