253440

Appears in sequences

• Triangle read by rows: T(n,k) = number of paths of n upsteps U and n downsteps D that contain k UUDs.at n=38A051288
• E.g.f.: x^3*exp(x)^2.at n=11A052771
• Number of integers less than A000108(n) relatively prime to A000108(n).at n=13A062624
• Number of strings over Z_4 of length n with trace 0 and subtrace 2.at n=10A068774
• S(n; 1,1) = S(n; 3,1) where S(n; t,s) is the number of length n 4-ary strings whose digits sum to t mod 4 and whose sum of products of all pairs of digits sum to s mod 4.at n=10A068778
• Number of strings over Z_4 of length n with trace 2 and subtrace 2.at n=10A068790
• Number of permutations of {1,2,...,n} that result in a binary search tree with the minimum possible height.at n=10A076615
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n, having k ddu's [here u = (1,1) and d = (1,-1)].at n=45A091894
• Triangle read by rows: T(n,k)=k^3*2^k*binomial(2n-k,n-k)/(2n-k) (1<=k<=n).at n=41A112327
• Number of circular permutations of {1, 2, ..., n}, where every next element in binary notation has ones at the same or adjacent positions of previous element's binary ones.at n=12A115507
• The n-th derivative of 1/x^x, evaluated at x=1.at n=11A176118
• Number T(n,k) of permutations of {1,2,...,n} that result in a binary search tree of height k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=59A195581
• a(n) = 2^(n-3)*binomial(n,4).at n=12A213432
• Number T(n,k) of permutations of {1,2,...,n} that result in a binary search tree of height k; triangle T(n,k), k>=0, k<=n<=2^k-1, read by columns.at n=15A244108
• a(n) = binomial(n+1,2)*n!/n!!.at n=10A293656
• Number of subsets of {1..n} containing n such that no two elements have the same sorted prime signature.at n=35A325263
• Number of subsets of {1..n} such that no two elements have the same sorted prime signature.at n=35A326438
• a(0) = 0, a(1) = 1; otherwise, a(n) = a(n-1) + a(m), where m is the greatest square < n.at n=46A392473