28199

Appears in sequences

• a(n) = prime(n)*prime(n+2).at n=37A090076
• Numbers k such that k^2 + 1 == 0 (mod 41^2).at n=33A157116
• a(n) = prime(n) times the n-th nonnegative noncomposite.at n=39A176098
• Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=52A261075
• Sum_{ i in 1..p-1, j in 1..p-1, i*j mod p = 1} i*j, where p = n-th prime.at n=14A272650
• Sequence of pairwise relatively prime numbers of class P_4 (see comment in A275246).at n=19A275248
• Numbers such that the sum of the reverse of their aliquot parts is equal to the reverse of the sum of their aliquot parts.at n=32A278948
• Numbers k such that 311*2^k+1 is prime.at n=9A322946
• Numbers m such that Stern polynomial B(m,x) has no irreducible polynomial factors that themselves are Stern polynomials. The initial a(1) = 1 is included by convention.at n=36A389918