21768

Appears in sequences

• Number of inequivalent binary [ n,3 ] codes of dimension <= 3 without zero columns.at n=32A034337
• Numbers k such that k*2^(k/2) + 1 is prime.at n=10A058767
• a(n) = 2^(n-1) * Sum_{k=0..n} ((n+k)!/(n-k)!)/k!.at n=3A072331
• Absolute value of second differences of A005849.at n=10A128194
• Number of 0..n arrays x(0..9) of 10 elements with zero 6th differences.at n=24A200333
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 430", based on the 5-celled von Neumann neighborhood.at n=37A272116
• Solutions x to the negative Pell equation y^2 = 72*x^2 - 1331712 with x,y >= 0.at n=10A281241
• a(n) = Sum_{1<=i<=j<=n} prime(i)*prime(j).at n=11A357251
• Array read by ascending antidiagonals: A(n, k) = (-1)^(n + k) * Sum_{j=0..k} j! * Stirling1(n, j) * Stirling1(k, j).at n=58A379820
• Array read by ascending antidiagonals: A(n, k) = (-1)^(n + k) * Sum_{j=0..k} j! * Stirling1(n, j) * Stirling1(k, j).at n=62A379820