43390

Appears in sequences

• Number of primes <= 2^n.at n=19A007053
• a(n) = pi(Mersenne(n)): index of n-th Mersenne prime.at n=6A059305
• Number of squared primes <= 2^n.at n=38A060967
• Number of primes < 2^prime(n).at n=7A086690
• Where records occur in A001917.at n=20A152597
• Number of primes less than 2^n.at n=18A185192
• Positions of record high water marks in A246024.at n=43A246026
• Number of (n+1)X(1+1) 0..1 arrays with each row and column prime, read as a binary number with top and left being the most significant bits.at n=17A261754
• Multi-table menage numbers T(n,k) for n,k >= 1 equals the number of ways to seat the gentlemen from n*k married couples at n round tables with 2*k seats each such that (i) the gender of persons alternates around each table; and (ii) spouses do not sit next to each other; provided that the ladies are already properly seated (i.e., no two ladies sit next to each other).at n=12A277256
• Table of generalized ménage numbers read by antidiagonals upward: T(n,k) is the number of permutations pi in S_k such that pi(i) != i, i+n (mod k) for all i; n, k >= 1.at n=63A341439
• Triangle read by rows of generalized ménage numbers: T(n,k) is the number of permutations pi in S_n such that pi(i) != i and pi(i) != i+k (mod n) for all i; n, 1 <= k < n.at n=30A354408
• Triangle read by rows of generalized ménage numbers: T(n,k) is the number of permutations pi in S_n such that pi(i) != i and pi(i) != i+k (mod n) for all i; n, 1 <= k < n.at n=33A354408
• Maximum value in the n-th row of A354408.at n=7A354409
• Least k such that the k-th prime number has exactly n ones in its binary expansion.at n=18A372517
• Sorted list of positions of first appearances in A014499 (number of ones in binary expansion of each prime).at n=18A372686