18057

Appears in sequences

• Integers n > 10563 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10563.at n=10A063064
• Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 6 which is flat, i.e., with all blocks in parallel position.at n=4A123796
• a(n) = 4*n^4 + 3*n^3 + 2*n^2 + n + 1.at n=8A130886
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (0, -1, 1), (0, 1, -1), (1, 1, 1)}.at n=8A149611
• a(n) = 13*n^2 + 7*n + 1.at n=36A168240
• Square array, read by antidiagonals, used to recursively calculate the Springer numbers A001586.at n=50A185418
• G.f.: x/exp( Sum_{n>=1} a(n)*x^n/n ) = Sum_{n>=1} moebius(n)*x^n.at n=17A195589
• a(n) = 2*a(n-1) + a(n-3), where a(0) = 3, a(1) = 1, a(2) = 2.at n=13A332491
• a(n) = 1 + Sum_{k=1..n-4} a(k) * a(n-k-4).at n=27A346076