211974

Appears in sequences

• Main diagonal of triangle A129577.at n=9A129579
• Eigentriangle for the Catalan triangle (c(x), xc(x)), A033184.at n=56A181644
• Numbers n for which there exists k < n such that A000203(k) = A000203(n) and A007947(k) = A007947(n), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n.at n=30A255335
• The least number k > A255334(n) for which A000203(k) = A000203(A255334(n)) and A007947(k) = A007947(A255334(n)), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n.at n=30A255423