40120

Appears in sequences

• Number of triangles in an n X n grid (or geoplane).at n=7A045996
• Numbers k that divide the average of prime(k) and prime(k+1).at n=10A066706
• Numbers k such that k divides prime(k) + prime(k+1).at n=16A066895
• Numbers k such that phi(4k-1) = sigma(k).at n=10A067235
• Numbers k such that sigma(prime(k) + 1) == 0 (mod k).at n=45A067759
• Numbers k such that prime(k+1)^2 == prime(k)^2 (mod k).at n=38A067783
• Numbers n such that prime(n) == -7 (mod n).at n=21A092049
• Numbers k such that prime(k + 1) == 7 (mod k).at n=17A105421
• Square array read by antidiagonals downwards: T(n,k) = number of ways to arrange k indistinguishable points on an n X n square grid so that no three points are collinear at any angle.at n=52A194193
• Second elementary symmetric function of the first n terms of (1,1,2,2,3,3,4,4,...).at n=31A203246
• Number of (w,x,y,z) with all terms in {1,...,n} and w+x<y+z.at n=17A212523
• Number of (n+5)X6 0..1 matrices with each 6X6 subblock idempotent.at n=8A224570
• T(n,k)=Number of (n+5)X(k+5) 0..1 matrices with each 6X6 subblock idempotent.at n=36A224577
• Number of (n+1)X(1+1) 0..3 arrays colored with the maximum plus the upper median plus the lower median of every 2X2 subblock.at n=2A236251
• Number of (n+1)X(3+1) 0..3 arrays colored with the maximum plus the upper median plus the lower median of every 2X2 subblock.at n=0A236253
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays colored with the maximum plus the upper median plus the lower median of every 2X2 subblock.at n=3A236254
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays colored with the maximum plus the upper median plus the lower median of every 2X2 subblock.at n=5A236254
• Triangle read by rows: T(n,k) (1 <= k <= n) = number of ways to choose three points from an n X k grid of points which are the vertices of a triangle of nonzero area.at n=35A334705