272483

Appears in sequences

• Numbers that are the product of a pair of twin primes.at n=24A037074
• Product of twin primes of form (4*k+1,4*k+3), k>0.at n=11A071697
• Numbers k such that k+1 and sigma(k)+1 are both perfect squares.at n=33A089954
• Numbers that are one less than a square and have exactly 4 divisors.at n=25A134020
• Members of A159053 which are not multiples of 3.at n=14A159054
• Semiprimes which are sub-perfect powers.at n=37A189045
• Numbers k that form a primitive Pythagorean triple with k' and sqrt(k^2 + k'^2), where k' is the arithmetic derivative of k.at n=27A210503
• Quasi-Carmichael numbers to exactly four bases.at n=10A257754
• Semiprimes p*q for which p and q are successive primes and their binary representations differ from each other in one bit position only.at n=27A261080
• Numbers n which are neither a prime nor a square of a prime such that there is no d, 2<=d<=n/2, which divides binomial(n-d-1,d-1) and is not coprime to n.at n=33A269135
• Numbers k such that k^2 + sopfr(k)^2 is a square, where sopfr = A001414.at n=27A386991