71104

Appears in sequences

• Numbers which can be expressed as the product of numbers made of only fours.at n=26A161142
• Numbers which can be expressed as the product of numbers made of only eights.at n=16A161146
• G.f. A(x) satisfies: 1 = Sum_{n>=0} (-1)^n * (n+1) * x^(n*(n+1)/2) * A(x)^(n+1) /( Product_{k=1..n+1} 1 - x^k*A(x) ).at n=9A338185
• a(n) is the number of 2 X 2 matrices over the integers mod n that are invertible mod n for every permutation of their elements.at n=15A367926
• a(n) = Sum_{k=0..floor(n/2)} 2^k * binomial(k,n-2*k)^2.at n=16A387476