27366

Appears in sequences

• Barely abundant numbers: abundant n such that sigma(n)/n < sigma(m)/m for all abundant numbers m<n, sigma(n) being the sum of the divisors of n.at n=26A071927
• Numbers n such that n/6 and prime(n)+/-n are all primes.at n=32A105550
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and 2*w^2 < x^2 + y^2.at n=36A211800
• Least integer b>2n+1 such that the numbers written as [1,3,...,2n-1,2n+1] and [2n+1,2n-1,...,3,1] in base b are both prime.at n=19A218465
• Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7.at n=4A251918
• Number of (n+2)X(5+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7.at n=2A251920
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7.at n=23A251923
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7.at n=25A251923
• Numbers k such that (41*10^k + 373)/9 is prime.at n=19A285377
• a(n) is the least k such that A345468(k) = 2*n-1.at n=42A345469