18945

Appears in sequences

• Numbers n such that h(n) = 3 h(n-1) where h(n) is the length of the sequence {n, f(n), f(f(n)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)at n=19A078420
• Number of parts that are multiples of 3 in all partitions of n.at n=33A116635
• a(n) = 74*n^2 + 1.at n=16A158742
• a(n) = 5^n*sum_{i=1..n} i^5/5^i.at n=5A218376
• Expansion of (1 + 6*x + x^2 + 12*x^3 - 2*x^4)/((1 - x)^4*(1 + x)^3).at n=35A268579
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = Sum_{j=0..n} k^(n-j) * j^k.at n=60A368504
• a(n) = Sum_{k=0..n} n^(n-k) * k^n.at n=5A368505