-1409

Appears in sequences

• a(n) = -n^2 + 9*n + 53.at n=43A126665
• Triangle read by rows: coefficients of a Bessel polynomial recursion: P(x, n) = 2*(n-1)*P(x, n - 1)/x - n*P(x, n - 2) with substitution x -> 1/y.at n=29A136668
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 315", based on the 5-celled von Neumann neighborhood.at n=21A271249
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(Product_{j=1..n} (1-x^j) - 1).at n=61A294254
• E.g.f.: exp((1-x)*(1-x^2)*(1-x^3)*(1-x^4) - 1).at n=6A294257
• Expansion of sqrt(2 / ( (1-6*x+25*x^2) * (1-5*x+sqrt(1-6*x+25*x^2)) )).at n=5A337394
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of sqrt(2 / ( (1+2*(k-4)*x+((k+4)*x)^2) * (1-(k+4)*x+sqrt(1+2*(k-4)*x+((k+4)*x)^2)) )).at n=26A337464
• a(n) = n! * Sum_{k=0..floor(n/2)} (-1)^k * (k+1)^(k-1) / (k! * (n-2*k)!).at n=6A361916