4150390625

Appears in sequences

• Numbers k such that k has at least two distinct prime factors and if a prime p divides k then (p-1) | (k-1) and (p+1) | (k+1).at n=4A079543
• Expansion of g.f. (1-8*x)/(1-25*x).at n=7A196676
• Records in A378865.at n=22A379673