18387

Appears in sequences

• a(n) = floor(n*(n-1)*(n-2)*(n-3)/31).at n=29A011941
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = (odd natural numbers).at n=25A024463
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = (odd natural numbers).at n=24A025083
• A089450 indexed by A000040.at n=13A089525
• A vector recursion sequence: k = -3; m = 3; l = -3; a(n)=k*{0,a(n-2),0}+m*{-(m-1)/m,a(n-1)}++m*{a(n-1),-(m-1)/m}+l*{0,0,a(n-4),0,0}.at n=39A152655
• A vector recursion sequence: k = -3; m = 3; l = -3; a(n)=k*{0,a(n-2),0}+m*{-(m-1)/m,a(n-1)}++m*{a(n-1),-(m-1)/m}+l*{0,0,a(n-4),0,0}.at n=41A152655
• Monotonic ordering of nonnegative differences 3^i-6^j, for 40>= i>=0, j>=0.at n=29A192151
• Number of 1-separable partitions of n; see Comments.at n=47A239467
• Number of (n+1)X(2+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=3A250988
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=13A250994
• Number of (4+1)X(n+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=1A250998
• Expansion of Product_{k>=1} 1/(1-x^(2*k-1))^(2*k-1).at n=24A262811
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 721", based on the 5-celled von Neumann neighborhood.at n=23A273447
• Expansion of Product_{k>=1} 1/(1+x^(2*k-1))^(2*k-1).at n=24A284628
• Number of numbers <= 10^n that are products of 5 distinct primes.at n=5A359644