-670

Appears in sequences

• a(n) = H_n(1) / 2^floor(n/2) where H_n is the n-th Hermite polynomial.at n=9A025165
• Product_{k>=1} ((1 + x^k)^a(k)) = 1 + 4x.at n=5A038069
• a(n) = Sum_{i=n-4..n-1} (-1)^i*a(i), a(1)=1, a(2)=1, a(3)=1, a(4)=1.at n=54A051793
• a(n) = Sum_{i=n-4..n-1} (-1)^i*a(i), a(1)=1, a(2)=1, a(3)=1, a(4)=1.at n=59A051793
• Site series for first perpendicular moment of 4.8 (bathroom tile) lattice.at n=16A120560
• Triangular sequence from coefficients of characteristic polynomial of n X n prime element matrices: M=A.B.A^(-1); (A(3) is singular): examples; A(4)= {{2, 3, 5, 7, 11}, {3, 5, 7, 11, 13}, {5, 7, 11, 13, 17}, {7, 11, 13, 17, 19}, {11, 13, 17, 19, 23}} B(4)= {{3, 5, 7, 11, 13}, {5, 7, 11, 13, 17}, {7, 11, 13, 17, 19}, {11, 13, 17, 19, 23}, {13, 17, 19, 23, 29}}.at n=21A137405
• Coefficient array for powers of x^2 of polynomials appearing in a generalized Melham conjecture on alternating sums of fifth powers of Chebyshev S polynomials with odd indices.at n=13A220671
• Expansion of Product_{k>=1} ((1 - k*x^k) / (1 - x^k)).at n=20A267005
• Recurrence a(n+2) = Sum_{k=0..n} binomial(n,k)*a(k)*a(n+1-k) with a(0)=1, a(1)=-2.at n=7A289068
• Expansion of 1/(2 - Product_{k>=1} 1/(1 + x^k)).at n=13A307060