52421

Appears in sequences

• Quasi-Carmichael numbers to base 5: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-5|n-5.at n=9A029558
• a(n) = numerator of (1/n^3)*(-1/(n+1) + 16/(n+2) + 3/(4*(2*n+1)) - 81/(4*(2*n+3))), term of a BBP-type series representation of zeta(3) by V. Adamchik and S. Wagon.at n=23A256323
• Number of integer partitions of n that contain at least one even part and whose halved even parts are relatively prime.at n=43A366845
• a(0) = 1; a(n) = a(n-1) + Sum_{k=0..n-1} (1 + k) * binomial(k+1,2) * binomial(n-1,k) * a(k) * a(n-1-k).at n=5A386510