20727

Appears in sequences

• Number of board-pile polyominoes with n cells.at n=9A001169
• Numbers k such that sigma(k) = sigma(k+7).at n=20A015867
• Fibonacci sequence beginning 0, 21.at n=16A022355
• a(n) = Fibonacci(n) * Fibonacci(2*n).at n=8A037451
• a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n-1 <= 2^(p+1), with a(1) = 1, a(2) = 3, and a(3) = 2.at n=16A049920
• Products of distinct terms of Fibonacci(2^(i+2)): a(n) = Product_{i=0..floor(log_2(n+1))} F(2^(i+2))^bit(n,i).at n=6A050615
• Numbers k such that k | 11^k + 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k.at n=39A057286
• E.g.f.: exp(x*exp(x*exp(x*exp(x))) + 1/3*x^3*exp(x*exp(x*exp(x)))^3).at n=6A060913
• Sum_{i=0..2*A053645(n)} (C(2*A053645(n),i) mod 2)*A000045(n-i) [where C(r,c) is the binomial coefficient (A007318) and A000045(n) is the n-th Fibonacci number].at n=22A075149
• First trisection of A028560.at n=47A147651
• a(n) = 81*n^2 - 9.at n=15A157909
• a(n) = 256*n^2 - n.at n=8A158010
• Number of ON cells at n-th stage of three-dimensional version of the cellular automaton A160117 using cubes.at n=17A160379
• a(n) = n^2*(2*n + 5).at n=21A163683
• Positions of 3's in A234323.at n=55A234804
• Number of partitions of n such that 2*(least part) < number of parts.at n=36A237758
• Number of length 4 arrays x(i), i=1..4 with x(i) in i..i+n and no value appearing more than 3 times.at n=10A250362
• a(n) is the least integer k such that there are n values of i <= k for which gpf(i^2 + 1) = gpf(k^2 + 1), where gpf(x) is the greatest prime factor of x.at n=28A258840
• Least number x such that x^n has n digits equal to k. Case k=5.at n=19A285452
• Number of partitions of an n-set without blocks of size 6.at n=9A343666