20255

Appears in sequences

• a(n) = Sum_{k=0..floor(n/2)} T(n-k,k), T given by A026769.at n=18A026779
• Semiprimes in A056108.at n=23A113527
• Numbers k such that 19^k - 2 is a prime.at n=16A128460
• Number of n X 3 binary arrays with all 1s connected, all corners 1, and no 1 having more than two 1s adjacent.at n=13A163734
• Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 10.at n=13A244711
• Number of integer partitions of n such that every pair of distinct parts has a different product.at n=38A325856
• Expansion of (1/x) * Series_Reversion( x*(1+x+x^3)/(1+x)^2 ).at n=16A366116
• Number of integer compositions of n matching both of the dashed patterns 23-1 and 1-32.at n=18A375297