27828

Appears in sequences

• a(n) = T(n,n-6), array T as in A055801.at n=32A055806
• a(n) = least positive k such that k, k+1, k+2, ..., k+n-1 is a stapled interval of length n, or 0 if no such sequence exists.at n=18A090318
• Row sums of triangle A101224, which is related to the Flavius sieve (A000960).at n=31A101105
• Number of unordered rooted trees where each subtree from given node has the same number of nodes.at n=31A127524
• Expansion of q^(-1/3) * (eta(q^3) / eta(q))^4 in powers of q.at n=13A128758
• "Stapled" intervals are defined in A090318. Call a stapled interval "maximal" if it is not a proper subinterval of any other stapled interval. Sequence gives starting points of maximal stapled intervals.at n=1A130170
• Starting points of stapled intervals.at n=1A130173
• floor((log(4)/log(3))^n).at n=44A140881
• Let J_n be n X n matrix which contains 1's only, I=I_n be the n X n identity matrix and P=P_n be the incidence matrix of the cycle (2,3,...,n,1). Then a(n) is the number of (0,1) n X n matrices A<=J_n-I-P with exactly two 1's in every row and column.at n=4A174564
• Numbers that are equal to the sum of the number of divisors of their first k arithmetic derivatives, for some k.at n=34A269459
• Number of nX2 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=7A278849
• T(n,k)=Number of nXk 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=37A278855
• T(n,k)=Number of nXk 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=43A278855
• a(0) = a(1) = 1; for n > 1, a(n) = Sum_{k=0..n-2} a(k) OR a(n-k-2).at n=17A318621
• Place n equally spaced points on each side of a square, and join each of these points by a chord to the 3*n new points on the other three sides: sequence gives number of edges in the resulting planar graph.at n=7A367279
• Table read by antidiagonals: Place k equally spaced points on each side of a regular n-gon and join every pair of these n*k points by a chord; T(n,k) (n >= 3, k >= 0) gives the number of edges in the resulting planar graph.at n=37A367305
• Irregular triangle read by rows: T(n,k) is the sum of all parts of all partitions of n with k designated summands, n >= 1, 1 <= k <= A003056(n).at n=57A386997