20947

Properties

Appears in sequences

• a(n) = A027052(n, 2n-2).at n=11A027058
• Numerators in expansion of exp(2x)/(1-x).at n=9A053484
• Primes p such that 6p + 1 and (p-1)/6 are primes.at n=34A085957
• Number of consecutive prime runs of 3 primes congruent to 3 mod 4 below 10^n.at n=6A092643
• Balanced primes of order eleven.at n=8A096703
• Primes in A126554.at n=7A126555
• Primes congruent to 24 mod 61.at n=36A142822
• Primes p such that (p-1)*p*(p+1)-p+2 and (p-1)*p*(p+1)+p-2 are primes.at n=31A154944
• Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >= 2n.at n=15A210367
• Number of (n+1) X (1+1) 0..2 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.at n=7A251130
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.at n=28A251137
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.at n=35A251137
• Primes p such that 2*p + 1 is abundant.at n=24A267476
• Number of nX4 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=9A301819
• Expansion of Product_{k>=1} 1/(1 + x^k)^(k+1).at n=40A305628
• The number of regions inside a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.at n=14A340685
• Primes p such that p^4 - 1 has 160 divisors.at n=43A341662
• Primes p such that p^8 - 1 has 384 divisors.at n=5A342064
• Number of integer partitions of n with origin-to-boundary graph-distance equal to 4.at n=63A384562
• Prime numbersat n=2356