321024

Appears in sequences

• a(n) is the decimal concatenation of n and n^2.at n=31A053061
• Expansion of (1-x)/(1+2*x-2*x^3).at n=27A078060
• Binomial transform of hexagonal pyramidal numbers A002412.at n=11A085385
• Numbers k = a * b, such that k' = a' * b' where k', a' and b' are the arithmetic derivatives of k, a and b.at n=31A294153