511969

Appears in sequences

• Numbers k such that k and k^2 use only the digits 1, 2, 5, 6 and 9.at n=41A137006
• a(n) = Sum_{k=1..n} k*A001168(k)*binomial(n-1,k-1), where A001168(k) is the number of fixed polyominoes with k cells.at n=8A343208