164640

Appears in sequences

• Theta series of direct sum of 4 copies of hexagonal lattice.at n=19A008655
• Numbers k such that the set of prime divisors of k is equal to the set of prime divisors of sigma(k).at n=24A027598
• a(n)=a(n-1)+a(n-2)-d, where d=a(n/5) if 5 divides n, else d=0; 2 initial terms.at n=26A050195
• Saint-Exupéry numbers: ordered products of the three sides of Pythagorean triangles.at n=36A057096
• Low-temperature specific heat expansion for square lattice (Potts model, q=3).at n=10A057376
• Number of endofunctions on n labeled points constructed from k rooted trees.at n=24A066324
• Numbers k such that [A070080(k), A070081(k), A070082(k)] is a right integer triangle with relatively prime side lengths.at n=19A070137
• Triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) = number of simple graphs on n labeled nodes with k edges where each maximally connected subgraph consists of a single node or has a unique cycle of length 4.at n=43A144209
• Triangle T(n, k) = coefficients of (p(x,n)), where p(x, n) = (n-1)! * Sum_{j=1..n} A142458(n, j)*binomial(x+j-1, n-1), read by rows.at n=29A168295
• Triangle, read by rows, T(n, k) = (-1)^n * n!/(k*k!) * binomial(n-1, k-1) * binomial(n, k-1).at n=32A176013
• Numbers which are the area of exactly three Pythagorean triangles.at n=18A177021
• Triangle a(n,k) = binomial(n,k)*binomial(n+1,k+1)*binomial(n+2,k+2) read by rows.at n=32A187552
• Numbers with prime factorization pqr^3s^5.at n=23A190475
• Triangular array read by rows: T(n,k) is the number of functions f:{1,2,...,n} -> {1,2,...,n} that have exactly k nonrecurrent elements; n>=1, 0<=k<=n-1.at n=24A219694
• Numbers n such that there are three distinct triples (k, k+n, k+2n) of squares.at n=8A222154
• Number of ascent sequences of length n with exactly three flat steps.at n=7A242156
• Terms of a particular integer decomposition of N^N.at n=32A243203
• a(n) = A025487(n) * A324576(n) = A025487(n) * A276086(A025487(n)).at n=15A324577
• Numbers k such that the squarefree kernel of sigma(k) is equal to the squarefree kernel of 2*k.at n=25A332208
• E.g.f. satisfies A(x) = exp(x^2*A(x)) / (1-x).at n=7A371038