44304

Appears in sequences

• Number of unrooted triangulations with reflection symmetry of a disk with 2 internal nodes and n+3 nodes on the boundary.at n=15A005509
• Number of permutations of {1,2,...,n} where adjacent elements differ in value by 3 or more.at n=10A127697
• Janet periodic table of the elements and structured hexagonal diamond numbers. a(n) = A166911(2*n) + A166911(2*n+1).at n=12A167471
• Number of permutations of 1..2*n+6 with no adjacent elements within n in value.at n=2A179964
• Noncrossing, nonnesting, 2-arc-colored permutations on the set {1..n} where lower arcs even of different colors do not cross.at n=7A219587
• Numbers that divide the reverse of the sum of their aliquot parts.at n=3A254005
• Numbers k such that (199*10^k - 7)/3 is prime.at n=23A281990
• Triangle T(n,k) giving the number of permutations of 1..n with no adjacent elements within k in value, for n >= 2, 1 <= k <= floor(n/2).at n=22A322255