20891

Appears in sequences

• Numbers whose base-12 representation has exactly 5 runs.at n=10A043654
• Determinant of n X n Hankel matrix whose entries are t(i+j), 0 <= i, j < n, where t is the Thue-Morse sequence.at n=34A056887
• Triangle T(n,k) of number of strongly connected digraphs on n unlabeled nodes and with k arcs, k=0..n*(n-1).at n=66A057276
• Triangle T(n,k) read by rows, giving number of matroids of rank k on n labeled points (n >= 0, 0 <= k <= n).at n=38A058669
• Triangle T(n,k) read by rows, giving number of matroids of rank k on n labeled points (n >= 0, 0 <= k <= n).at n=42A058669
• Number of matroids of rank 2 on n labeled points.at n=8A058681
• Fourth column of A046741.at n=16A062124
• Numbers n for which there are exactly ten k such that n = k + reverse(k).at n=21A072434
• Numbers k such that 7*10^k + 9 is prime.at n=29A097954
• Expansion of psi(x^2) / f(-x) in powers of x where psi(), f() are Ramanujan theta functions.at n=33A098613
• A triangular array of numbers related to factorization and number of parts in Murasaki diagrams.at n=48A133611
• Triangle read by rows, A008277 * A000012.at n=38A137650
• Indices j in A000040 such that j is an odd composite and the distinct digits of the prime A000040(j) are in increasing order.at n=40A155775
• T(n,k) = number of nonnegative integer arrays of length n+k-1 with new values 0 upwards introduced in order, and containing the value k-1.at n=42A211561
• Number of nonnegative integer arrays of length n+6 with new values 0 upwards introduced in order, and containing the value n-1.at n=2A211566
• G.f.: Product_{k>=1} 1/(1-x^k)^(3*k+2).at n=8A255803
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 97", based on the 5-celled von Neumann neighborhood.at n=32A270154
• Numbers n such that prime(n) contains a substring of all the prime digits in order, i.e., "2357".at n=12A295708
• Number of weak compositions of n such that the set of adjacent differences is a subset of {-1,1}.at n=22A383620