28050

Appears in sequences

• Number of labeled trees of diameter 3 with n nodes.at n=7A000554
• Number of labeled trees with n nodes and 9 leaves.at n=1A055321
• Numbers n that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (n raised to k+1 must not be a multiple). Case k=10.at n=35A135195
• Alexandrian integers: numbers of the form n = p*q*r such that 1/n = 1/p - 1/q - 1/r for some integers p,q,r.at n=25A147811
• 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, -1), (-1, 0, 0), (0, -1, 1), (1, -1, 1), (1, 1, 0)}.at n=9A149252
• A symmetric triangle, with sum the large Schröder numbers.at n=48A175124
• A symmetric triangle, with sum the large Schröder numbers.at n=51A175124
• Numbers n such that n!10-1 is prime.at n=36A204658
• Triangle T(n,k) read by rows, where T(n,k) is the number of k-dimensional faces of the polytope that is the convex hull of all permutations of the list (0,1,...,1,2), where there are n - 1 ones, for n > 0. T(0,0) is 1.at n=62A259569
• Triangle read by rows, T(n,k) = Sum_{j=0..n} (-1)^(n-j)*C(-j-1,-n-1)*S1(k,j), S1 the Stirling cycle numbers A132393, for n>=0 and 0<=k<=n.at n=42A271700
• a(n) = 3*(9*n - 1)*(3*n - 2).at n=19A277985
• Unitary practical numbers that are nonsquarefree.at n=20A287173
• Numbers of the form A000217(n)*A007494(n) that are divisible by 3.at n=27A295867
• Irregular table: the n-th row polynomial is given by the formal power series expansion of Sum_{k >= 0} (1 + q)^(n*k + n^2)*Product_{j = 1..k} (1 - (1 + q)^(2*j-1)), n >= 1.at n=29A340882
• a(n) = Sum_{k=0..floor(n/5)} binomial(n+4,5*k+4) * Catalan(k).at n=13A360047
• Triangle read by rows, T(n, k) = binomial(n, k) * k! * Stirling2(n-k, k), for n >= 0 and 0 <= k <= n//2, where '//' denotes integer division.at n=38A362369
• Number of permutations of [n] with the property that no subsequence k(k+1)(k+2) or (k+2)(k+1)k occurs but k(k+1) or (k+1)k occurs.at n=8A370485