4226417

Appears in sequences

• Expansion of Sum_{n>=0} x^n * Sum_{k=0..n} C(n,k)^2 * x^(2*k).at n=23A246840
• The smallest positive number k such that the sum of the products of its digits when written in all bases 2 to n equals k, or -1 if no such number exists.at n=44A376860