57728

Appears in sequences

• a(n) = [ (3rd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+2 positive integers congruent to 1 mod 3}.at n=18A024220
• a(n) = Sum_{k=1..n} k*(prime(k) - k).at n=31A110477
• Number of ways to place 2 queens on an n X n chessboard so that they attack each other.at n=32A144945
• a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 277) or the same sequence for the mesh pattern (12, 337).at n=11A289604
• Numbers k such that k divides sigma(A003961(k)), where A003961 is fully multiplicative with a(p) = nextprime(p), and sigma is the sum of divisors function.at n=31A389469