19922944

Appears in sequences

• a(n) = n*2^n - 2^n = 2^n*(n-1).at n=19A058922
• Number of plane binary trees of size n+3 and contracted height n.at n=17A074092
• Denominators in the Maclaurin series for arctan(1+x).at n=37A075554
• a(n) = n-th n-almost prime.at n=20A101695
• a(n) = 19*2^n.at n=20A110288
• a(n) = 4^n*Lucas(n), where Lucas = A000032.at n=9A127211
• a(n) = 2^(n-1)*A047240(n).at n=20A128205
• a(n) = n*2^floor((n+1)/2).at n=38A132314
• a(n) = n*2^(floor(n/2)).at n=38A132344
• a(0) = 9, a(n) = 2*a(n-1) + 2^(n-1) for n > 0.at n=20A159697
• a(n) = n*4^(n/2 - 1)*(9 + (-1)^n).at n=19A187274
• (n-1)-st elementary symmetric function of the first n terms of (2,2,1,2,2,1,2,2,1,...)=(A130196 for n>0).at n=28A203167
• Number of (n+1) X (n+1) 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock differing from the number in all its horizontal and vertical neighbors.at n=17A205064
• Number of permutations of length n containing exactly 1 occurrence of 123 and 2 occurrences of 132.at n=19A224289
• Number of n X 4 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, 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=5A233164
• Number of n X 6 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, 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=3A233166
• 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, diagonally, 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=39A233168
• 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, diagonally, 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=41A233168
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1 + x + 2*x^2)^n.at n=40A251687
• Triangle for denominators of coefficients for integrated odd powers of cos(x) in terms sin((2*m+1)*x).at n=64A273172