18436

Appears in sequences

• Let r, s, t be three permutations of the set {1,2,3,..,n}; a(n) = value of Sum_{i=1..n} r(i)*s(i)*t(i), with r={1,2,3,..,n}; s={n,n-1,..,1} and t={n,n-2,n-4,...,1,...,n-3,n-1}.at n=21A070893
• Expansion of (1+x+x^2)/((1+x^2)*(1+x)^4*(1-x)^5).at n=42A082290
• Numbers equal to a permutation (or rearrangement) of the digits of the sum of their proper divisors (excluding the proper divisor 1). Rearrangements which cause leading zeros are excluded.at n=11A086248
• Number of regions formed inside square by diagonals and the segments joining the vertices to the points dividing the sides into n equal length segments.at n=32A108914
• Number of connected simple graphs with n vertices, n+6 edges, and vertex degrees no more than 4.at n=9A112426
• G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) * (1-x^27) * (1-x^30) * (1-x^33) / (1-x)^11.at n=7A162628
• Number of two-sided n-step prudent walks ending on the top side of their boxes, avoiding exactly two consecutive west steps and south steps.at n=12A190735
• Number of (w,x,y,z) with all terms in {1,...,n} and 2|w-x|<=n+|y-z|.at n=12A212690
• Numbers n such that n*2^2203 - 1 is prime.at n=23A265503
• Numbers k for which A019565(2k)-1 is a multiple of A000265(phi(A019565(2k))).at n=35A339973
• Number of edges in a square when n internal squares are drawn between the 4n points that divide each side into n+1 equal parts.at n=48A357061
• E.g.f. satisfies A(x) = 1 + (exp(x*A(x)^3) - 1)/A(x).at n=5A377324