20420

Appears in sequences

• Triangle of 3-Eulerian numbers.at n=24A144697
• Numbers k such that 58/111*(10^(3*k)-1)-1 is prime.at n=12A178321
• Partial sums of the tricapped prism numbers A005920.at n=14A187673
• Number of formula representations of n using addition, exponentiation and the constant 1.at n=10A214843
• G.f. A(x) satisfies: A(x) = 1 + x + x^3 * A(x/(1 - x)) / (1 - x).at n=14A346052
• a(n) = Sum_{k=0..floor(n/2)} binomial(k+3,3) * binomial(k,n-2*k)^2.at n=14A377149