57026

Appears in sequences

• Numbers whose Matula tree is a binary tree (i.e., root has degree 2 and all nodes except root and leaves have degree 3).at n=21A111299
• a(n) = ceiling(A003269(n)/2).at n=39A173674
• Number of triples (a, b, c) with gcd(a, b, c) = 1 and -n <= a,b,c <= n.at n=20A175549
• Triangle read by rows: row n>=1 contains in increasing order the Matula numbers of the rooted binary trees with n leaves.at n=21A245824
• Number of surviving even nodes at generation n in the binary tree of persistently squarefree numbers (see A293230).at n=39A293518
• Matula-Goebel numbers of unlabeled binary rooted semi-identity trees.at n=12A339193