-681

Appears in sequences

• A generalized Jacobsthal sequence.at n=11A083943
• Expansion of (1-x)*(2*x^2+2*x+1) / ((x^2-x-1)*(x^2+x+1)).at n=14A111734
• Triangle read by rows of coefficients of Chebyshev-like polynomials P_{n,4}(x) with 0 omitted (exponents in increasing order).at n=48A136390
• a(n) = (5 + (-2)^n)/3.at n=11A140966
• Expansion of (1-2x-5x^2-7x^3+x^6)/((1-x)(1-x^3)^2).at n=31A141352
• Second right hand column of the Beta triangle A160480.at n=6A160483
• Inverse binomial transform of A084640.at n=11A171501
• Sequence with Hankel transform equal to the Somos-4 sequence A006769(n+2).at n=16A178072
• a(n) = Hypergeometric([-n, n], [1], 2).at n=5A182626
• G.f.: imaginary part of 1/(1 - i*x - i*x^2) where i=sqrt(-1).at n=20A201838
• a(n) = ((n^2+1)^3) - s, where s is the nearest square to (n^2+1)^3.at n=8A233149
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 379", based on the 5-celled von Neumann neighborhood.at n=15A271538
• G.f. A(x) satisfies: A(x) = Product_{k>=1} 1/(1 + x^k*A(x)^k)^k.at n=9A301831
• Expansion of Product_{k>=1} 1/(1 + x^k)^p(k), where p(k) = number of partitions of k (A000041).at n=21A304784
• E.g.f. satisfies log(A(x)) = exp(x / A(x)^3) - 1.at n=4A363302
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A384896.at n=51A384901