1703936

Appears in sequences

• a(n) = 13*2^n.at n=17A005029
• a(n) = (3*n-2)*2^(n-3).at n=16A066373
• Products of exactly 18 primes (generalization of semiprimes).at n=12A069279
• Number of plane binary trees of size n+3 and contracted height n.at n=14A074092
• a(n) is the number of occurrences of 7's in the palindromic compositions of 2*n-1, or also, the number of occurrences of 8's in the palindromic compositions of 2*n.at n=16A079861
• a(n) = (2*n+1) * (2*n)! / (sqrt(4*(n+1)*Product_{k=1..2*n+1} lcm(k, 2*n+2-k))).at n=23A082292
• a(1) = 1. For n >=2, a(n) = the smallest integer > a(n-1) such that both a(n) and a(n)-a(n-1) have the same number of (non-leading) 0's when they are represented in binary.at n=37A160825
• 3-level binary fanout graph coloring a rectangular array: number of nX1 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,3 1,4 0,2 2,5 2,6 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=18A223417
• Number of defective 4-colorings of an n X 2 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..3 order.at n=15A229572
• Numerator of 2n/v(n)^2, where v(1) = 0, v(2) = 1, and v(n) = v(n-1)/(n-2) + v(n-2) for n >= 3; limit of 2n/v(n)^2 is Pi.at n=12A239224
• Row sums of A146565.at n=21A259098
• Numbers k such that the sum of the distinct digits of k is equal to the product of the prime divisors of k.at n=25A357263