65051

Appears in sequences

• a(n) = p(1)p(n) + p(2)p(n-1) + ... + p(k)p(n+1-k), where k = [ (n+1)/2 ], p = A000040 = the primes.at n=39A024697
• a(n) = p(1)p(n) + p(2)p(n-1) + ... + p(k)p(n-k+1), where k = [ n/2 ], p = A000040, the primes.at n=39A025129
• Triangle read by rows: matrix cube of the Stirling2 triangle A008277.at n=22A039811
• Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-0100 pattern in any orientation.at n=10A146713
• a(n) is the least integer k such that 1/(Sum_{j=1..n} 1/phi(k*j)) is an integer.at n=32A341810
• a(n) is the least integer k such that n/(Sum_{j=1..n} 1/phi(k*j)) is an integer.at n=32A341813
• Expansion of e.g.f. (exp(exp(exp(x)-1)-1)-1)^2 / 2.at n=5A351513
• a(n) = 4*a(n-1) -5*a(n-2) +2*a(n-3) +2*a(n-4) for a(0) = a(1) = 0, a(2) = 1, a(3) = 4 for n >= 4.at n=14A373358
• Total number of 321 patterns in all heapable permutations of length n.at n=9A392533