20539

Appears in sequences

• dot product (n,n-1,...2,1).(3,4,...,n,1,2).at n=44A026054
• Numbers k such that gcd(3k,8^k+1) = 3 but k does not divide the numerator of B(2k) (the Bernoulli numbers).at n=31A070193
• a(1)=1. Thereafter, a(n) = n*a(n-1) if the number of divisors of n*a(n-1) is <= the number of divisors of n+a(n-1) or a(n) = n+a(n-1) if n*a(n-1) has more divisors than n+a(n-1).at n=18A134189
• Numbers n such that primorial(n)/2 + 8 is prime.at n=25A139441
• Numerator of Euler(n, 5/29).at n=3A157340
• a(n) = n^2 + a(n-1), with a(1)=0.at n=38A168559
• Great rhombicuboctahedron with faces of centered polygons.at n=9A193252
• Number of partitions of n such that (number parts having multiplicity 1) is a part and (number of parts > 1) is not a part.at n=41A241513
• a(n) = a(n-1) * (11*a(n-1) - 16*a(n-2)) / (a(n-1) + 10*a(n-2)) with a(1) = 1, a(2) = 2.at n=11A247518
• Expansion of Product_{k>=1} 1/(1 - x^k)^(p(k)-p(k-1)), where p(k) = number of partitions of k (A000041).at n=24A304967
• a(0) = 0, a(1) = 1. For n >= 2, a(n) = a(n-1)/(n-1) if n-1 divides a(n-1); otherwise, a(n) = a(n-1) + a(n-2).at n=40A343376
• Radicands of pure cubic number fields of type BETA and subtype M0.at n=23A363699
• a(n) = Sum_{k=0..floor(n/3)} binomial(4*n-k+1,n-3*k).at n=5A371775