18937

Appears in sequences

• a(n+1) = 1 + a( floor(n/1) ) + a( floor(n/2) ) + ... + a( floor(n/n) ).at n=46A003318
• Numbers k such that the continued fraction for sqrt(k) has period 93.at n=14A020432
• Numbers whose base-5 representation contains exactly three 1's and three 2's.at n=30A045232
• Number of preferential arrangements for the set partitions of the n-set [1,2,3,...,n].at n=6A083355
• Numbers n such that the numerator of Sum_{i=1..n} (1/i^2), in reduced form, is prime.at n=33A111354
• a(n) = 6 + floor((1 + Sum_{j=1..n-1} a(j))/3).at n=28A120152
• 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, 0), (0, -1, 1), (1, 0, 1), (1, 1, -1)}.at n=9A148858
• Array read by antidiagonals of higher order Fubini numbers.at n=26A153278
• Number of n X 2 binary arrays with every 1 having exactly one king-move neighbor equal to 1.at n=11A183435
• Number of arrays of -4..4 integers x(1..n) with every x(i) in a subsequence of length 1 or 2 with sum zero.at n=7A193644
• Number of nondecreasing -n..n vectors of length 5 whose dot product with some other -n..n vector equals 5.at n=7A226344
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 379", based on the 5-celled von Neumann neighborhood.at n=29A271537
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. 1/(1 - f^k(x)), where f(x) = exp(x) - 1.at n=42A363007
• G.f.: 1/Product_{k>=1} (1 - x^(3*k^2)) * (1 - x^k).at n=32A385012