57556

Appears in sequences

• Numerator of 4 * H(n,4,1), a generalized harmonic number. See A075136.at n=4A074598
• Number of compositions of n with parts in N which avoid the adjacent pattern 111.at n=18A128695
• Start from the singleton set S = {n}, and unless 1 is already a member of S, generate on each iteration a new set where each odd number k is replaced by 3k+1, and each even number k is replaced by 3k+1 and k/2. a(n) is the total size of the set from the singleton through after the first iteration which has produced 1 as a member, inclusive.at n=38A291213
• a(n) = Sum_{k=0..n} 2^(n-k) * binomial(3*n,k).at n=6A385004