21856

Appears in sequences

• Number of circulant tournaments on 2n+1 nodes up to Cayley isomorphism.at n=18A002086
• Octahedral numbers: a(n) = n*(2*n^2 + 1)/3.at n=32A005900
• Number of nonisomorphic circulant tournaments, i.e., Cayley tournaments for cyclic group of order 2n-1.at n=19A049288
• 2-boustrophedon transform (see A059294) of 1, 1, 1, 1, ...at n=7A059295
• Number of subsets of {1,2,3,...,n} that sum to 0 mod 3.at n=16A068010
• Number of subsets of {1,2,3,...,n} that sum to 0 mod 6.at n=17A068012
• Number of subsets of {1,2,3,...,n} that sum to 0 mod 12.at n=18A068033
• a(n) = (2*8^n + 2^n)/3.at n=5A082412
• a(n) = 10*a(n-2) - 16*a(n-4) for n>=4, with a(0)=a(1)=1, a(2)=6, a(3)=10.at n=10A083333
• Expansion of 1/sqrt(1-16x-16x^2).at n=4A106260
• phi(n) + n is a cube.at n=31A114074
• Centered 47-gonal numbers.at n=30A129428
• Last occurrence of n partitions in A204814.at n=31A205301
• Number of (n+1)X(3+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..3+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=4A233299
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..k+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=25A233301
• Number of (5+1) X (n+1) 0..1 arrays x(i,j) with row sums Sum_{j=1..n+1} x(i,j) nondecreasing, and column sums Sum_{i=1..5+1} i^2*x(i,j) nondecreasing.at n=2A233305
• Rounded down ratio of a minimum intersection area with a unit circle area in n-symmetrical unit circles intersect in a single point.at n=30A243933
• The second Zagreb index of the Aztec diamond AZ(n) (see the Ramanes et al. reference, Theorem 2.2).at n=17A292345
• Number of primes less than 10^n with digits in nonincreasing order.at n=12A345326
• Partial sums of the even triangular numbers (A014494).at n=31A352115