18984

Appears in sequences

• Numbers whose base-4 representation contains exactly three 0's and four 2's.at n=31A045056
• a(n) = Sum_{k=1..n} lcm(n,k).at n=41A051193
• Nonprimes in the triangle A141020.at n=27A141031
• a(n) = 1728*n - 24.at n=10A157287
• E.g.f. satisfies: A(x) = A(x)^2*(1 + x*A(x))/(1+x) - x*A'(x).at n=6A179496
• The sum of the elements within a jump in a Sieve of Eratosthenes table.at n=29A179545
• Sequences from the quartic oscillator.at n=5A228406
• Sum of numbers in the n-th antidiagonal of the reciprocity array of 0.at n=42A259574
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 209", based on the 5-celled von Neumann neighborhood.at n=30A270893
• Numbers k such that 5*10^k + 87 is prime.at n=28A271360
• Number of integer partitions of n whose Durfee square has sides of even size.at n=40A274523
• Partial sums of A006010.at n=14A335648
• G.f. A(x) satisfies A(x) = ( (1 + x*A(x)^2)/(1 - x*A(x)) )^3.at n=4A379245
• Triangle read by rows: T(n,k) is the number of regions between the free polyominoes, with n cells and length k, and their bounding boxes, n >= 1, k >= 1.at n=73A380284
• Numbers x such that there exist three integers 0<x<=y, z>0 and w>0 such that sigma(x)^3 = sigma(y)^3 = x^3 + y^3 + z^3 + w^3.at n=30A385397