26004

Appears in sequences

• G.f. satisfies A(x) = 1 + x*cycle_index(G,A(x)) where G = cyclic group of order 2 generated by (1,2)(3,4)(5,6)(7,8).at n=6A036725
• A triangle of coefficients of polynomials with roots as the Pi-digits base ten A000796(n)=d(n):d(1)=3; p(x,n)=-d(1)*Product[x-d(m),{m,2,n}].at n=30A152575
• Number of different fixed (possibly) disconnected trominoes bounded (not necessarily tightly) by an n*n square.at n=11A162673
• Numbers k such that 9*R_(k+2) - 4*10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=20A257039
• a(n) is the number of states that can be achieved when starting from n piles each containing one stone, where any number of stones can be transferred between piles that start with the same number of stones.at n=37A292726
• a(n) = 102*2^n - 108 (n>=1).at n=7A304830
• a(n) = 108*n^2 - 104*n + 20 (n>=1).at n=15A304835
• One of the four successive approximations up to 13^n for the 13-adic integer 6^(1/4). This is the 4 (mod 5) case (except for n = 0).at n=7A325487
• a(n) is the cyclic length of the iterative sequence f(k) = prime(f(k-1) mod 2^n) with f(0) = 1.at n=29A326613
• Number of ways to select 3 or more collinear points from an n X n grid.at n=9A355553
• a(n) = Sum_{j=0..n} C(n)*C(n-j), where C(n) is the n-th Catalan number.at n=6A358436
• a(n) = Sum_{k=1..n} (-1)^(k-1) * binomial(floor(n/k)+3,4).at n=26A366659
• Coefficient of x^n in the expansion of ( (1+x)^2 * (1+x+x^2)^2 )^n.at n=5A370160
• Coefficient of x^n in the expansion of 1 / ( (1-x) * (1-x+x^2) )^(2*n).at n=5A372464
• G.f. A(x) satisfies A( A(x)^2 - x^2 ) = 4*A(x)^3.at n=6A389542