20384

Appears in sequences

• Number of nonequivalent dissections of an n-gon into n-4 polygons by nonintersecting diagonals rooted at a cell up to rotation.at n=6A003443
• Let sigma_m (n) be result of applying sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m (n) = k*n; sequence gives the (4,k)-perfect numbers.at n=46A019293
• Theta series of A*_13 lattice.at n=61A023925
• a(n) = n + (n+1)^2 + (n+2)^3.at n=25A027620
• Even numbers to the right of the central numbers of the (1,2)-Pascal triangle A029635.at n=38A029643
• Even numbers to the left of the central elements of the (2,1)-Pascal triangle A029653.at n=41A029665
• a(n) = binomial(n+5,5)*(n+3)/3.at n=11A040977
• T(n,4), array T as in A050186; a count of aperiodic binary words.at n=24A050189
• Numbers k that can be expressed as k = w + x = y*z with w*x = y^3 + z^3 where w, x, y, and z are all positive integers.at n=32A057372
• Numbers n such that sopf(n) = sopf(n+1) - sopf(n-1), where sopf(x) = sum of the distinct prime factors of x.at n=10A076525
• a(n) = the number of aperiodic subsets S of the n-th roots of 1 with zero sum (i.e., there is no r different from 1 such that r*S=S).at n=35A110981
• Triangular matrix T, read by rows, that satisfies: SHIFT_LEFT(column 0 of T^p) = p*(column p+2 of T), or [T^p](m,0) = p*T(p+m,p+2) for all m>=1 and p>=-2.at n=29A111536
• Column 1 of triangle A111536.at n=6A111537
• Determinants of 5 X 5 matrices consisting of 25 consecutive primes.at n=7A118815
• Nonisomorphic catacondensed monoheptafusenes (see reference for precise definition).at n=8A121073
• Number of jumps in all binary trees with n edges.at n=8A127531
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (0, 1, -1), (1, 0, 0), (1, 1, -1)}.at n=10A148330
• a(n) = n*(n+2)^2.at n=26A152619
• Minimal covering numbers.at n=18A160559
• Triangle read by rows: T(n,k) = number of pairs of partitions of n that have block distance k (n >= 2, 2 <= k <= n).at n=22A193297