28273

Appears in sequences

• Numbers k such that 203*2^k + 1 is prime.at n=19A032478
• Composite numbers whose prime factors contain no digits other than 5 and 7.at n=34A036320
• Numbers that are the product of 3 prime factors whose concatenation is a palindrome.at n=40A046452
• Partial sums of 3-almost primes which are again 3-almost primes, i.e., have exactly 3 not necessarily distinct prime factors.at n=32A217018
• Triangle read by rows: T(m,n) is the label of the ending square of an (m,n)-leaper (a generalization of a chess knight) when it can no longer move, starting on a board with squares spirally numbered, starting at 1; 1 <= n < m. Each move is to the lowest-numbered unvisited square.at n=11A323750