28757

Appears in sequences

• a(1) = 7; a(n+1) = a(n)-th composite.at n=40A025011
• Numbers whose base-13 representation has exactly 5 runs.at n=13A043660
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 9.at n=26A051974
• Odd composite numbers which in base 2 contain their largest proper factor as a substring of digits.at n=35A063131
• Composite numbers not divisible by 2, 3, 5 or 7 which in base 2 contain their largest proper factor as a substring.at n=29A063138
• Composite numbers not divisible by 2 which in base 4 contain their largest proper factor as a substring.at n=12A063145
• m for which p(m) is the least prime dividing #p(n) + 1, i.e., primorial n-th prime augmented by 1 (A005234).at n=28A068488
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=27A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=28A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=29A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=30A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=31A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=32A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=33A077658
• Least composite number not congruent to 0 (modulo the first n primes) which contains its greatest proper divisor as a substring of itself, both in base two.at n=34A077658
• prime(n)*( prime(n)-n ).at n=43A161522
• Number of n-step three-sided prudent self-avoiding walks ending on the left side of their box.at n=11A191826
• Number of 3X3X3 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors, and every horizontal row having the same average value.at n=23A214541
• Indices of octagonal numbers (A000567) that are also centered heptagonal numbers (A069099).at n=7A254855
• Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=54A261075