18942

Appears in sequences

• Sum{T(i,n-i): i=0,1,...,n}, array T as in A047150.at n=15A047151
• a(n) = Sum_{k=1..prime(n)-1} floor(k^3/prime(n)).at n=13A078837
• T(n,k) counts the set partitions of n containing k-1 blocks of length 1.at n=50A086659
• Let X be the poset of finite subsets of the positive integers. The sequence is the number of downsets in X of cardinality n modulo equivalence by permutations of the positive integers.at n=20A087729
• Number of magic labelings of the Petersen graph with magic sum n.at n=12A125196
• a(n) = 11*n*(n+1).at n=41A164136
• Number of connected regular simple graphs on n vertices with girth exactly 3.at n=12A186743
• Principal diagonal of the convolution array A213819.at n=20A213820
• Expansion of (1+4*x+x^2)/((1+x)^2*(1-x)^5).at n=21A233329
• A255475(2^n-1).at n=7A255476
• Triangle T(n, k) = the number of point-labeled graphs with n points and k edges, no points isolated, no edges isolated. By rows, 0 <= n, ceiling(2*n/3) <= k <= binomial(n, 2).at n=27A276640
• Number of set partitions of [n] into exactly six blocks where sizes of distinct blocks are coprime.at n=5A280884
• Number of non-derogatory n X n matrices with elements {-1, 0, 1}.at n=2A306817
• Number of triangular regions in the Farey Diagram Farey(n,n), divided by 4.at n=7A358302
• G.f. satisfies A(x) = ( 1 + x*A(x)^3 * (1 + x*A(x)) )^2.at n=5A371575
• Expansion of (1/x) * Series_Reversion( x / (1 + x^3 / (1 - x)^3) ).at n=13A389250