-1681

Appears in sequences

• Numerator of [x^n] in the Taylor series arccosh(exp(x)-arctanh(x))= x-x^2/6-x^3/72 -359*x^4/2160 -1681*x^5/51840 -52981*x^6/435456 -...at n=4A013325
• Expansion of (1-x)^(-1)/(1+2*x-x^2).at n=9A077921
• Expansion of 1/(1+x+x^2+2*x^3).at n=27A077976
• A triangular sequence of polynomial coefficients of an adjusted root product one polynomial set: w(i,n)=If[i == 1, 1/n!, i]; p(x,n)=n!*Product[x - w[i, n], {i, 0, n}]/x.at n=19A142148
• Convolution of A006352 and A010815.at n=70A143278
• Numerator of Euler(n, 1/6).at n=5A156187
• Numerators of the second differences of the sequence of fractions (-1)^(n+1)*A176618(n)/A172031(n).at n=15A195240
• Bisection of A195240(n).at n=7A228954
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 483", based on the 5-celled von Neumann neighborhood.at n=31A272346
• Dirichlet g.f.: 1 / zeta(s-2).at n=40A334657
• a(1) = 1, a(2) = -5; a(n) = -n^2 * Sum_{d|n, d < n} a(d) / d^2.at n=40A359485
• a(1) = 1, a(2) = 3; a(n) = n^2 * Sum_{d|n, d < n} (-1)^(n/d) a(d) / d^2.at n=40A361986
• a(1) = 1; a(n) = n^2 * Sum_{d|n, d < n} (-1)^(n/d) a(d) / d^2.at n=40A361987