39479

Appears in sequences

• Numbers n such that d(n + d(n)) = d(n), where d(n) is the sum of the distinct primes dividing n.at n=36A175760
• The number of symmetric positive definite 2 X 2 matrices whose entries are integers of absolute value at most n.at n=34A219693
• Numbers x such that sigma(x)=sigma(V(x)), where sigma(x) is the sum of the divisors of x and V(x) the transform defined in A245252.at n=13A245469
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 873", based on the 5-celled von Neumann neighborhood.at n=31A273709
• Products p*q*r of three distinct primes such that (p*q) mod r, (p*r) mod q and (q*r) mod p are all prime.at n=39A338704
• Products p*q*r of three distinct primes such that s=(p*q) mod r, t=(p*r) mod q and u=(q*r) mod p, and s+t+u are all prime.at n=4A338705