33558528

Appears in sequences

• a(n) = (2^n + 2^[ n/2 ] )/2.at n=24A001445
• a(n) = 2^(n-1)*(2^n - (-1)^n).at n=13A003674
• Number of (n-1)-bead black-white reversible strings; also binary grids; also row sums of Losanitsch's triangle A034851; also number of caterpillar graphs on n+2 vertices.at n=26A005418
• a(n) = 2^(n-1)*(1+2^n).at n=13A007582
• Sum of every 4th entry of row n in Pascal's triangle, starting at "n choose 1".at n=27A038504
• Sum of every 4th entry of row n in Pascal's triangle, starting at binomial(n,2).at n=27A038505
• Number of elements of GF(2^n) with trace 0 and subtrace 1.at n=27A038519
• Number of elements of GF(2^n) with trace 1 and subtrace 0.at n=27A038520
• Number of undirected walks of length n+1 on an oriented triangle, visiting n+2 vertices, with n "corners"; the symmetry group is C3. Walks are not self-avoiding.at n=25A051437
• Number of compositions of n with an odd number of 1's.at n=26A113980
• a(2n) = 2^(2n), a(2n+1) = 2^(2n+1) + a(n).at n=25A127804
• A006516 at positions with even indices, A007582 at positions with odd indices.at n=27A137173
• Half the number of n X 2 0..2 arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors.at n=12A183495
• Number of n X 2 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabeled 8-colorings with no clashing color pairs).at n=7A233196
• T(n,k)=Number of nXk 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs).at n=37A233202
• Triangular numbers representable as 2^x + 2^y.at n=14A262242
• a(n) = (1/2) * Sum_{k=0..n-1} binomial(4*n,4*k+2).at n=7A387742