18512790

Appears in sequences

• a(n) = floor(2^n / n).at n=28A000799
• Number of degree-n irreducible polynomials over GF(2); number of n-bead necklaces with beads of 2 colors when turning over is not allowed and with primitive period n; number of binary Lyndon words of length n.at n=29A001037
• Product_{k>=1}1/(1 - x^k)^a(k) = 1 + 2x.at n=28A038063
• Product_{k>=1} (1 + x^k)^a(k) = 1 + 2x.at n=28A038067
• A simple grammar: cycles of pairs of sequences.at n=29A052823
• a(n) = (1/n) * Sum_{ d divides n } mu(n/d) * (2^d - 1).at n=28A059966
• Number of orbits of length n in map whose periodic points are A000051.at n=28A060477
• Number of orbits of length n in map whose periodic points come from A059990.at n=28A060480
• Number of subsets of {1,2,..n} that sum to 1 mod n.at n=28A064355
• a(n) = (2^prime(n)-2)/prime(n); a(0) = 0 by convention.at n=10A064535
• a(n) = round( 2^n/n ).at n=28A065482
• a(n) = floor of (2^n-1)/n.at n=28A082482
• a(n) = A086323(n)/n.at n=28A086442
• Number of n-bead necklaces using exactly three colors with no adjacent beads having the same color.at n=28A093367
• a(n) = Sum_{k=0..n} floor(binomial(n,k)/(k+1)).at n=27A095718
• a(n) = A056188(n)/n.at n=28A098792
• Number of necklaces with n beads of 3 colors, no 2 adjacent beads the same color.at n=28A106365
• Related to sums of the n-th roots of unity: sums in a circular wedge (excluding the origin).at n=28A107847
• (1/n)*A204991(n).at n=28A204992
• Express 1 - x - x^2 - x^3 - x^4 - ... as product (1 + g(1)*x) * (1 + g(2)*x^2) *(1 + g(3)*x^3) * ... and use a(n) = - g(n).at n=28A220418