21184

Appears in sequences

• Numbers k such that (k / product of digits of k) is 1 or a prime.at n=38A001103
• Partial sums of A034953(n).at n=21A085739
• Triangle read by rows: T(n,k) is the number of ordered trees with n edges and having k branches of odd length (n>=0, 0<=k<=n).at n=73A102003
• Row sums of triangle A115237.at n=30A115238
• G.f. satisfies: A(x) = Sum_{n>=0} x^n * (1 + A(x))^(2*n) * A(x)^(n^2).at n=4A192260
• Number of solutions to n = Sum_{i=1..pi(n-1)} c(i)*p(i) with c(i) in {-1,0,1}, p(n) = n-th prime and pi = A000720.at n=44A215222
• Expansion of e.g.f.: -LambertW(-x) / LambertW(x).at n=6A215882
• Sum of the parts in the partitions of 4n into 4 parts with smallest part = 1.at n=15A239056
• Numbers for which the cube of the sum of the digits is equal to the square of the product of their digits.at n=29A241846
• Numbers n such that A002496(n) mod A002496(n-1) is a perfect square.at n=43A247592
• p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - S^2 - S^3.at n=19A291736
• Smallest k > 0 with gcd(k, rev(k)) = n, where rev(k) is digit reversal of k and with sum of digits of k = n, or 0 if no such k exists.at n=15A333666
• Array read by antidiagonals: T(n,k) is the determinant of the Hankel matrix of the 2*n-1 consecutive primes starting at the k-th prime, n >= 0, k >= 1.at n=52A350200