268419072

Appears in sequences

• Expansion of g.f.: 2*x*(1-x)/((1-2*x)*(1-2*x^2)).at n=28A014236
• a(n) = 4^n - 2^n.at n=14A020522
• Number of reversible strings with n beads of 2 colors. If more than 1 bead, not palindromic.at n=28A032085
• Sum of every 4th entry of row n in Pascal's triangle, starting at "n choose 1".at n=30A038504
• Number of elements of GF(2^n) with trace 1 and subtrace 1.at n=30A038521
• Number of 2n-bead balanced binary necklaces which are equivalent to their reversed complement, but not equivalent to their reverse and complement.at n=29A045678
• Number of 2n-bead balanced binary necklaces of fundamental period 2n which are equivalent to their reversed complement, but are not equivalent to their reverse and complement.at n=29A045687
• Number of words of length 2n in the two letters s and t that reduce to the identity 1 by using the relations ssTT=1, ststSS=1 and ststTT=1, where S and T are the inverses of s and t, respectively (i.e., sS=1 and tT=1). The generators s and t and the three stated relations generate the quaternion group Q4.at n=14A071930
• Number of strings of length n over GF(4) with trace 0 and subtrace 1.at n=15A073996
• Sum of odd entries in row n of Pascal's triangle.at n=29A088560
• Number of compositions of n with an odd number of 1's.at n=29A113980
• G.f.: 1/((1-2*x)*(1-2*x^2)).at n=27A122746
• a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) for n >= 4 starting with a(0) = 1, a(1) = 2, a(2) = 4, and a(3) = 6.at n=29A131885
• a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3), n > 3; a(0) = 1, a(1) = 4, a(2) = 12, a(3) = 32.at n=26A133212
• The number of length n binary words with some prefix which contains two more 1's than 0's or two more 0's than 1's.at n=28A233411
• Number of non-palindromic n-tuples of 4 distinct elements.at n=13A242026
• Number of length n+2 0..1 arrays with the sum of the maximum minus twice the median plus the minimum of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=26A251421
• 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 213", based on the 5-celled von Neumann neighborhood.at n=27A279879
• 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 469", based on the 5-celled von Neumann neighborhood.at n=27A282417
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 107", based on the 5-celled von Neumann neighborhood.at n=28A285835