87480

Appears in sequences

• Triangle of coefficients in expansion of (3+5x)^n.at n=37A013622
• Specific heat coefficients for square lattice spin 3 Ising model.at n=42A030122
• Number of necklaces with n labeled beads of 3 colors.at n=5A032179
• Scaled Chebyshev U-polynomials evaluated at i*3/2. Generalized Fibonacci sequence.at n=5A057092
• a(n) = binomial(n + 7, 7)*9^n.at n=3A173192
• Numbers k such that rad(k)^2 divides sigma(k).at n=14A173615
• Numbers m such that, in the prime factorization of m, the product of the exponents equals the sum of prime factors and exponents.at n=19A231231
• Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.at n=22A257620
• Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.at n=26A257620
• Number of n X 2 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two exactly once.at n=7A268633
• T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two exactly once.at n=37A268639
• T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.at n=43A269035
• Expansion of Product_{k>=1} ((1 + x^k) / (1 - x^(5*k)))^k.at n=23A285459
• Numbers k = a * b, such that k' = a' * b' where k', a' and b' are the arithmetic derivatives of k, a and b.at n=20A294153
• Triangle read by rows T(n,k): number of undirected cycles of length k in the complete tripartite graph K_{n,n,n} (n = 1...; k = 3..3n).at n=17A296546
• Triangle read by rows: T(0,0) = 1; T(n,k) = T(n-1,k) + 9 * T(n-2,k-1) for k = 0..floor(n/2); T(n,k)=0 for n or k < 0.at n=52A317051
• Triangle read by rows. T(n, k) = [x^k] P(n, x), where P(n, x) = Sum_{k=0..n} 2^(n - k) * Sum_{j=0..k} (x^j * binomial(k, j) * (2*j + 1)^n), (secant case).at n=22A363398
• Triangle read by rows. T(n, k) = [x^k] P(n, x), where P(n, x) = Sum_{k=0..n} 2^(n - k) * Sum_{j=0..k} (x^j * binomial(k, j) * ((2 - (n mod 2)) * j + 1)^n).at n=22A363400