41104179200domain: NAppears in sequencesExpansion of (1+2*x) / (1-2*x)^4.at n=23A014483Sums of the squares of the elements in the subsets of the integers 1 to n.at n=24A087076Numbers of isomers of unbranched a-4-catapolypentagons - see Brunvoll reference for precise definition.at n=27A121135