19868

Appears in sequences

• Third convolution of A001405 (central binomial numbers).at n=10A054443
• Numbers k such that h(k) = h(k-1) + h(k-2), where h(k) = A006577(k) + 1 is the length of the sequence {k, f(k), f(f(k)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)at n=38A078418
• Solution to the non-squashing boxes problem (version 2).at n=32A089055
• Number of binary strings of length n avoiding "squares" (that is, repeated blocks of the form xx) with |x| > 3.at n=15A230177
• Number of standard Young tableaux with n cells and exactly seven successions.at n=6A241778
• Number of standard Young tableaux with 2n cells and exactly n successions.at n=7A241785
• Triangle read by rows: T(n,k) number of ways of partitioning the (n+5)-element multiset {1,1,1,1,1,1,2,3,...,n} into exactly k nonempty parts, n >= 0 and 1 <= k <= n + 5.at n=90A291120
• Number of nX6 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=2A302963
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=30A302965
• Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=5A302966
• Triangle of optimist numbers T(n,k) (n >= 1, 0 <= k <= n-1) read by rows: permutations needing k steps to be sorted by the "optimist" algorithm.at n=31A345453