187705

Appears in sequences

• Number of ways to place 3 nonattacking kings on a 3 X n board.at n=36A172202
• Numbers k such that one of k-A001414(k) and k+A001414(k) is a prime and the other is the square of a prime.at n=26A358002
• Irregular triangle read by rows. Properly color the vertices of a simple labeled graph on [n] using exactly n colors c_1<c_2<...<c_n (in other words, use each color exactly once). Orient the edges according to the strict order on the colors. T(n,k) is the number of such graphs with exactly k descents, n>=0, 0<=k<=binomial(n,2).at n=35A381192