64704

Appears in sequences

• Triangle of numbers T(n,k) = T(n-1,k-1) + ((n+k-1)/k)*T(n-1,k), n >= 1, 1 <= k <= n, with T(n,1) = n!, T(n,n) = 1; read from right to left.at n=51A059369
• a(n) = A080315(n) - 2^A000523(A080315(n)), i.e., the terms of A080315 without their most significant bit.at n=16A080316
• A014486-encoding of the Catalan mountain ranges with only even-length slopes allowed.at n=21A083932
• Triangle T(n, k) read by rows. T(n, k) is the number of lists of k unlabeled permutations whose total length is n.at n=59A090238
• Number of binary strings of length n with equal numbers of 00001 and 10100 substrings.at n=17A164206
• Arises in enumerating Huffman codes, compact trees, and sums of unit fractions.at n=18A194631
• Number of 2 X 2 nonsingular matrices having all terms in {1,...,n}.at n=15A211056
• a(n) is the number of regular hexagons with all six vertices (x,y,z) in the set {1,2,...,n}^3.at n=16A338322