3440640

Appears in sequences

• Theta series of D*_15 lattice.at n=31A022068
• Number of rooted graphs on n labeled nodes where the root has degree 2.at n=4A038094
• Denominators of coefficients in the formal power series a(x) such that a(a(x)) = exp(x) - 1.at n=8A052105
• Number of endofunctions on n labeled points constructed from k rooted trees.at n=31A066324
• Products of exactly 18 primes (generalization of semiprimes).at n=29A069279
• a(n) = 2^n*binomial(n,2).at n=15A100381
• Denominators of coefficients in a series solution to a certain differential equation.at n=4A104997
• Five-coordinate renormalization of A_5 to pentadentate D_2 polynomial as a coefficient expansion.at n=2A115348
• a(n) = A203315(n)/A000178(n) where A000178=(superfactorials).at n=5A203317
• 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=32A219694
• Terms of a particular integer decomposition of N^N.at n=40A243203
• Intersection of A025487 and A026477.at n=29A275911
• Denominators of coefficients in asymptotic expansion of C_n (number of connected chord diagrams, A000699).at n=8A280777
• Number of n X 3 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=15A281200
• Triangle read by rows: T(n,k) is the number of nodes of degree k counted over all simple labeled graphs on n nodes, n>=1, 0<=k<=n-1.at n=23A285529
• Triangle read by rows: T(n,k) is the number of nodes of degree k counted over all simple labeled graphs on n nodes, n>=1, 0<=k<=n-1.at n=25A285529
• Nonprime Heinz numbers of integer partitions whose product is equal to their sum.at n=31A301988
• Number of ways to choose a factorization of each integer from 2 to n into factors > 1.at n=24A321514
• E.g.f.: C(x,q) = 1 + Integral S(x,q) * C(q*x,q) dx, such that C(x,q)^2 - S(x,q)^2 = 1, where C(x,q) = Sum_{n>=0} sum_{k=0..n*(n-1)/2} T(n,k)*x^n*y^k/n!, as an irregular triangle of coefficients T(n,k) read by rows.at n=91A322218
• a(n) is the number of subsets of {1,2,...,n} that contain exactly two odd numbers.at n=29A330592