47940

Appears in sequences

• Iterative "rewrite" sequence of binary plane trees.at n=3A057119
• The binary encoding (as a rooted planar tree) of each rooted planar binary tree. See A057123 for illustration.at n=12A057122
• Numbers k such that sigma(k+1) divides sigma(k), where sigma(k) is the sum of positive divisors of k.at n=38A058073
• (1,3) entry of powers of the orthogonal design shown in A090592.at n=11A089181
• Numbers k such that sigma(k) = 3*sigma(k+1).at n=3A217791
• Expansion of Product_{k>=1} (1 + (k-1)*x^k).at n=28A267007
• Magic sums of 4 X 4 magic squares composed of odd squares.at n=27A271582
• Number of words of length n, over the alphabet {a,b,c}, which have an odd number of a's and the number of b's plus the number of c's is less than or equal to 3.at n=34A342159