20757

Appears in sequences

• Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 18 (most significant digit on right).at n=23A029511
• Numbers k such that 2^k - 3 is prime.at n=39A050414
• Smallest odd number k such that p(2m)-2p(m)=k has exactly n solutions (where p(m) = m-th prime).at n=12A069890
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 1), (1, -1, 1), (1, 0, -1), (1, 1, 1)}.at n=8A149628
• Number of lattice paths from (0,0) to (n,n) using steps (1,0), (1,1), (1,2), and (2,1).at n=10A191354
• a(n) = (n+1)*(n-2)*(n-3)/2.at n=34A212343
• Number of 3 X 3 X 3 triangular 0..n arrays with every horizontal row nondecreasing, first elements of rows nonincreasing, last elements of rows nondecreasing, and every row having the same average value.at n=33A215183
• Composite squarefree numbers k such that the arithmetic mean of the distinct prime factors of k is a prime p, and p divides k.at n=32A229094
• Convolution of nonzero octagonal numbers (A000567) with themselves.at n=8A276159
• 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 870", based on the 5-celled von Neumann neighborhood.at n=14A284305
• Squarefree numbers k such that the sum of the distinct prime factors of k is twice the difference between the largest and the smallest prime factors of k.at n=22A324210