-1134

Appears in sequences

• a(n) = (3^n/n!) * Product_{k=0..n-1} (3*k - 2).at n=5A004989
• Expansion of cos(sin(log(1+x))).at n=7A009036
• Expansion of e.g.f.: cos(tanh(log(1+x))).at n=7A009084
• Glaisher's chi_4(n).at n=44A030212
• Determinant of the n X n Hankel matrix whose entries are s_2 (i+j), 0 <= i, j < n, where s_2 is the sum of the base-2 bits.at n=27A056886
• Triangle of coefficients, read by rows, where T(n,k) is the coefficient of x^n*y^k in f(x,y) that satisfies f(x,y) = 1/(1-x) - x^2/(1-x)^2 + xy*f(x,y)^2.at n=50A086610
• Let M be a diagonal matrix with A007442 on the diagonal and P = Pascal's triangle as an infinite lower triangular matrix. Now read the triangle P*M by rows.at n=50A124800
• Expansion of ((b(q)*c(q))^3 - 8*(b(q^2)*c(q^2))^3) / 27 in powers of q where b(), c() are cubic AGM theta functions.at n=17A128486
• Triangle of coefficients of characteristic polynomials of anti-symmetrical tridiagonal matrices: Middle diagonal: a=1; Lower first subdiagonal: b=2; Upper first subdiagonal: c=-2; Example: M(3) {{1, -2, 0}, {2, 1, -2}, {0, 2, 1}}.at n=50A136643
• Fibonacci matrix read by antidiagonals. (Inverse of A136158.)at n=41A164948
• Totally multiplicative sequence with a(p) = 9*(p-3) for prime p.at n=33A167319
• Triangle read by rows, e.g.f. exp(x*(z+3/2))/((exp(3*x/2)+2*cos(sqrt(3)*x/2))/3).at n=49A215062
• Triangle read by rows, e.g.f. exp(x*z)*((exp(x/2)+exp(x*3/2))/((exp(3*x/2)+ 2*cos(sqrt(3)*x/2))/3)-1).at n=49A215064
• Expansion of (psi(x) * phi(-x)^4)^2 in powers of x where phi(), psi() are Ramanujan theta functions.at n=11A215472
• Triangle read by rows, Bell transform of the complementary Bell numbers (A000587).at n=51A264435
• a(n) = Sum_{d divides n} (-1)^(d + n/d) * d^3.at n=9A321559
• Dirichlet g.f.: zeta(2*s) / (zeta(s) * zeta(s-3)).at n=19A328640
• Dirichlet g.f.: 1 / zeta(s)^9.at n=47A341835
• a(n) = Sum_{k=1..n} (-1)^k*k^2*floor(n/k).at n=38A366915