201326590

Appears in sequences

• a(n) = 3*2^n - 2.at n=26A033484
• a(3) = 1, otherwise a(n) = n*2^(n-3) - 2^(n-2) - 2.at n=23A058966
• a(n) = B(2*n, 2)/B(2*n) (see formula section).at n=13A096045
• Expansion of x*(3*x^2+x+1)/((x-1)*(2*x-1)*(x+1)).at n=27A192033
• a(0)=0, a(1)=1, for n>1, a(n) = n<*>n, where k<*>m = k<+>k<+>...<+>k is the m-1-fold iteration of the operation <+> defined in A206853.at n=24A206960
• a(n) = 3*2^n - 2*(-1)^n.at n=26A259713
• a(0) = 1, a(n+1) = 2*a(n) + periodic sequence of length 2: repeat [5, -4].at n=26A280173
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 621", based on the 5-celled von Neumann neighborhood.at n=27A283357
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 637", based on the 5-celled von Neumann neighborhood.at n=27A283406
• Number of bisymmetric, quasitrivial, and order-preserving binary operations on the n-element set {1,...,n}.at n=27A296953
• a(n) = n! * [x^n] (2*x - 4*exp(x) + 3*exp(2*x) + 3) / 2.at n=27A369491