32028

Appears in sequences

• Number of permutations of length n with two 3-sequences.at n=9A002630
• Triangle of numbers a(n,k) = number of permutations on n letters containing k 3-sequences (n >= 0, 0<=k<=max(0,n-2)).at n=40A047921
• A triangular sequence based on a further generalization of the Cornelius-Schultz matrix polynomials to two sequences in i and j. a(n)=(n-1)!/f[n]: f[n]-> Fibonacci numbers; c(n)=1/n; B(i,j)=(-1)^(i + j)*a[j + 1]*c[i + 1]/(j!*(i - j)!) as a lower triangular matrix.at n=17A135256
• Number of right triangles on a (n+1)X6 grid.at n=26A189810
• Number of (n+2) X (3+2) 0..3 arrays with every consecutive three elements in every row and column not having exactly two distinct values, and in every diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=20A253020
• Related to enumeration of sets of non-intersecting circles in the plane.at n=9A281346
• Numbers k such that (299*10^k + 1)/3 is prime.at n=20A294911
• Number of non-unimodal compositions of n covering an initial interval of positive integers.at n=17A332743
• Midpoints k of a pair of twin primes such that sigma(k) is also the midpoint of a pair of twin primes.at n=39A349981
• Number of (binary) heaps of length n whose element set is a subset of [n].at n=7A373450