27721

Appears in sequences

• Maximal number of pairwise relatively prime polynomials of degree n over GF(2).at n=19A001115
• Number of paraffins.at n=48A005999
• Smallest k>1 such that k(p-1)-1 is divisible by p^2, p=n-th prime.at n=38A039914
• a(n) = 1 + lcm(1..k) where k is the n-th prime power A000961(n).at n=8A051452
• Smallest number that is centered polygonal in exactly n ways.at n=17A063773
• Least x greater than 1 such that x^n == 1 (mod i) for each i=1,2,3,...,n.at n=10A071553
• a(n) = 1 + lcm(1, 2, ..., n) = 1 + A003418(n).at n=11A075059
• a(n) = 1 + lcm(1, 2, ..., n) = 1 + A003418(n).at n=12A075059
• p^2-p-1 that is not prime, where p is prime.at n=21A119609
• Inverse Mobius transform of the superabundant numbers, A051731 * A004394.at n=22A134672
• Highly composite numbers + 1.at n=24A135372
• a(n)=a(n-1)+3a(n-2)+a(n-3).at n=13A137199
• a(n) = (3 + 2*n + 6*n^2 + 4*n^3)/3.at n=27A166464
• Numbers k such that A(k+1) = A(k) + 1, where A() = A005101() are the abundant numbers.at n=31A169822
• Numbers k for which d(k-1) + d(k+1) is a record, where d(k) is the number of divisors of k.at n=36A189828
• Centered 44-gonal numbers.at n=35A195318
• Number of (w,x,y,z) with all terms in {0,...,n} and w=max{w,x,y,z}-min{w,x,y,z}; i.e., the range of (w,x,y,z) is its first term.at n=24A212744
• Number of second differences of arrays of length 5 of numbers in 0..n.at n=10A228220
• a(n) = Sum_{i=0..n} digsum_9(i)^3, where digsum_9(i) = A053830(i).at n=58A231686
• Numbers n of the form p^2-p-1 = A165900(p), for prime p, such that n^2-n-1 = A165900(n) is also prime.at n=7A237527