26423

Properties

Appears in sequences

• Primes that are each the sum of two, three, and four consecutive composite numbers.at n=33A060339
• 30*a(n) is the gap between sexy prime triples in the n-th sexy prime triple triple whose initial term is 7.at n=15A090776
• Number of Dyck paths with no UUU's and no DDD's, of semilength n and having no UDUD's (U=(1,1), D=(1,-1)).at n=21A166289
• In binary starting with 1, prepend a 1 and as few 0's as required such that the new number is relatively prime to all previous in sequence. Thus binary 1, 11, 111, 10111, 110111, 100110111, 1100110111, 11100110111.at n=9A168612
• a(n) = 81*n^2 - 2247*n + 15383.at n=32A182255
• a(n) = 9*b_9(n) + 8, where b_9 lists the indices of zeros of the sequence A261309: u(n) = abs(u(n-1) - gcd(u(n-1), 9n-1)), u(1) = 1.at n=3A186261
• a(n) is the largest prime factor of n*2^n-1.at n=18A367003
• Primes having only {2, 3, 4, 6} as digits.at n=42A386140
• Prime numbersat n=2903