21183

Appears in sequences

• Ruth-Aaron numbers (1): sum of prime divisors of n = sum of prime divisors of n+1.at n=22A006145
• Continued fraction for log(89).at n=5A016517
• Sum of n plus its prime factors associated with A020700.at n=27A020905
• a(n) = (2*n+1)*(9*n+1).at n=34A033573
• Dirichlet convolution of d(n) (# of divisors) with Bell numbers.at n=9A034775
• Pseudo-random numbers: a (very weak) pseudo-random number generator from the second edition of the C book.at n=17A061364
• Numbers k such that sopfr(k) = sopf(k+1), where sopf(k) = A008472(k) and sopfr(k) = A001414(k).at n=19A064675
• Multiples of 23 whose digit reversal - 1 is also a multiple of 23.at n=37A166400
• Powers of sqrt(5) - 1 rounded down.at n=46A179241
• Number of n X 7 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing.at n=5A224145
• Number of 6 X n 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing.at n=6A224150
• Number of balanced ternary words of length n.at n=27A260938
• 11-gonal numbers which are products of three distinct primes.at n=18A354446
• Sum of maximum depths over all increasing rooted trees with n nodes.at n=7A390861