30213

Appears in sequences

• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,0,2,1.at n=4A037771
• One of the three sequences associated with the polynomial x^3 - 2.at n=14A052101
• Expansion of e.g.f.: exp(x)*sec(2*x).at n=7A117437
• Union of A052103, A052102 and A052101, uniqued and sorted.at n=35A140495
• Constant term of the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=18A192954
• G.f. A(x) satisfies: A(x)^3 + A(-x)^3 = 2 and A(x)^-3 - A(-x)^-3 = -18*x.at n=5A196864
• 1/4 the number of n X n 0..3 symmetric matrices with every element equal to zero or one horizontal and vertical neighbors.at n=3A211077
• Numbers k in A228058 such that also A001065(k) is in A228058.at n=38A325380
• E.g.f. (exp(x) - 1)/cos(2*x).at n=6A380056