4793490

Appears in sequences

• Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged.at n=28A000048
• a(n) = floor(2^(n-1)/n).at n=27A006788
• a(n) = floor(2^(n+2)/7).at n=22A033138
• Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,2.at n=11A037497
• Number of binary vectors (x_1,...x_n) satisfying Sum_{i=1..n} i*x_i = 3 (mod n+1) = size of Varshamov-Tenengolts code VT_3(n).at n=27A054200
• Nearest integer to 2^(n-1)/n.at n=27A054650
• Number of monic irreducible polynomials over GF(4) of degree n with fixed nonzero trace.at n=13A054660
• Number of primitive (period n) n-bead necklace structures using exactly two different colored beads.at n=27A056303
• Expansion of 1/(1 - x - x^2 - 2*x^3).at n=23A077947
• Numbers whose base-8 or octal representation is 22222222.......2.at n=8A125835
• a(n) + a(n+1) + a(n+2) = 2^n.at n=24A152732
• A023001 interleaved with 2*A023001 and 4*A023001.at n=25A155803
• Moore lower bound on the order of a (9,g)-cage.at n=13A198309
• a(n) = (Product_{i=1..n-1} (2^i + 1)) modulo (2^n - 1).at n=23A219732
• Renyi-Ulam liar numbers: maximum k such that n questions "Is x in subset S of {1,...,k}?" are guaranteed to determine x when at most one answer can be a lie.at n=27A286496