18134

Appears in sequences

• Numbers k such that both the k-th and (k+1)-th primes have the same sum of digits squared but different sets of digits.at n=4A109183
• Number of 5-element nondividing subsets of {1, 2, ..., n}.at n=25A187492
• Number of partitions of n where the difference between consecutive parts is at most 5.at n=39A238865
• Numbers k such that 3*R_k + 50 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=18A256800
• Convolution of A006068 (inverse of Gray code) with itself: a(n) = Sum_{k=1..n+1} A006068(k) * A006068(1+n-k).at n=42A268721
• Composite numbers k such that phi(x) = psi(k)*phi(k) has no solution.at n=11A292714
• Number of positive integers with a shortest addition-subtraction chain of length n.at n=18A383143