38121

Appears in sequences

• Riordan array ((1-x^2)/(1+3x+x^2),x/(1+3x+x^2)).at n=48A110168
• a(n) is the smallest number k larger than a(n-1) such that n*d(k)*sopf(k)=sigma(k), where d is the number of divisors (A000005) and sopf the sum of prime factors without repetition (A008472).at n=27A134382
• Odd composite integers m such that A006497(m) == 3 (mod m).at n=36A335669
• Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 3 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=3 and b=-1, respectively.at n=25A337626
• 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=36A338704