93496

Appears in sequences

• Number of unlabeled 4-gonal cacti having n polygons.at n=9A054362
• Numbers k such that 20*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=23A056656
• Numbers n such that { x +- 2^k : 0 < k < 4 } are primes, where x = 210*n - 105.at n=28A061671
• Numbers k such that phi(k) = sigma(core(k)) where phi(k) is the Euler totient function, sigma(k) the sum of divisors of k and core(k) the squarefree part of k (the smallest integer such that k*core(k) is a square).at n=11A069552
• Numbers n such that sigma(n) = 5*phi(n).at n=13A136547
• Numbers whose ternary and Zeckendorf representations are both palindromic.at n=9A329459
• The Fuss-Catalan triangle of order 3, read by rows. Related to quartic trees.at n=51A355174
• E.g.f. satisfies A(x) = 2/(3 - exp(2*x*A(x)^2)).at n=5A371298
• Numbers k such that sigma(k) = psi(k) + phi(k).at n=19A389478