25506

Appears in sequences

• Number of signed graphs with n nodes. Also number of 2-multigraphs on n nodes.at n=6A004102
• Table T(n,k) giving number of k-multigraphs on n nodes (n >= 1, k >= 0) read by antidiagonals.at n=33A063841
• Number of fault-free domino tilings (or dimer coverings) of a 2n X 2n square.at n=3A124997
• Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and pyramid weight k.at n=48A129163
• Sums of the products of n consecutive pairs of numbers.at n=26A135036
• Numbers k such that k and k^2 use only the digits 0, 2, 3, 5 and 6.at n=54A136888
• a(n) = (2*n^3 + 9*n^2 + n + 24) / 6.at n=41A160805
• Numbers k such that Sum_{d|k} sigma(d)^3/d is an integer, where d are the divisors of k.at n=10A226566
• Subsequence of lesser of 2 terms of A095301 that are 2 apart.at n=7A248083
• Array read by descending antidiagonals: A(n,k) is the number of unoriented colorings of the edges of a regular n-dimensional simplex using up to k colors.at n=25A327084
• Expansion of e.g.f. Sum_{k>=1} (exp(x) - 1)^k / (k * (1 - (exp(x) - 1)^k)^2).at n=5A330449
• 10^n-th nonsquarefree number.at n=4A374812
• E.g.f. satisfies A(x) = exp( 3 * (exp(x) - 1) * A(x)^(1/3) ).at n=5A375877
• a(n) = Sum_{k=0..n} binomial(n,k)^3 * Stirling2(2*k,k) * Stirling2(2*n-2*k,n-k).at n=4A384472