42180

Appears in sequences

• Numbers k such that sopfr(k) = sopfr(k - sopfr(k)).at n=32A050781
• Row sums of triangle A134480.at n=36A134481
• a(n) = A016755(n) - A001845(n).at n=18A188050
• Antidiagonal sums of the convolution array A213849.at n=35A213850
• a(n) = n*(2*n+1)*binomial(n+2,n)/3.at n=18A289643
• Number of n X 2 0..1 arrays with each 1 adjacent to 0, 1 or 3 king-move neighboring 1s.at n=9A296645
• Expansion of 1/(1 - Sum_{k>=1} x^prime(k)/(1 - x^prime(k))).at n=24A300671
• Midpoints k of a pair of twin primes such that sigma(k) is also the midpoint of a pair of twin primes.at n=44A349981