22499

Appears in sequences

• a(n) = (4*n+1)*(4*n+3).at n=37A001539
• Products of 2 successive primes.at n=34A006094
• Numbers that are the product of a pair of twin primes.at n=11A037074
• a(n) is the smallest composite number c such that A002110(n) + c is prime.at n=34A038771
• Numerators of continued fraction convergents to sqrt(214).at n=8A041398
• Numerators of continued fraction convergents to sqrt(856).at n=8A042652
• Smallest solution m to (n+1)*phi(m) = n*sigma(m), or -1 if no solution exists.at n=36A065824
• a(n) = A065824(A047845(n+1)).at n=16A065884
• Product of twin primes of form (4*k+1,4*k+3), k>0.at n=6A071697
• Multiplicative closure of twin prime pair products (A037074).at n=24A074480
• a(n) = least semiprime with factors not previously used containing integers 2n and 2n+1 as substrings.at n=7A086887
• a(n) = prime(2*n-1)*prime(2*n).at n=17A089581
• Numbers n such that n+1 and phi(n)+1 are both perfect squares.at n=22A089952
• Numbers k such that k+1 and sigma(k)+1 are both perfect squares.at n=15A089954
• Integer part of n#/(p-3)#, where p=preceding prime to n.at n=34A102790
• Integer part of n#/(p-5)#, where p=preceding prime to n.at n=33A102791
• Integer part of n#/(p-7)#, where p=preceding prime to n.at n=32A102792
• Numbers that are one less than a square and have exactly 4 divisors.at n=12A134020
• a(n) = 36n^2 - 1.at n=24A136017
• a(n) = 625*n - 1.at n=35A158374