28774

Appears in sequences

• Numbers whose base-13 representation has exactly 5 runs.at n=28A043660
• Semiprime centered triangular numbers.at n=50A184481
• Number T(n,k) of equivalence classes of ways of placing k 3 X 3 tiles in an n X 8 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=3, 0<=k<=2*floor(n/3), read by rows.at n=50A238558