87001

Appears in sequences

• a(n) = n^2*(2*n^2 + 1)/3.at n=19A071270
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, -1, 0), (0, 1, -1), (1, 1, 1)}.at n=9A149681
• Number of different fixed (possibly) disconnected tetrominoes bounded tightly by an n X n square.at n=11A163434
• T(n,m)=Number of (n+1)X5 0..m arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors.at n=37A189174
• Number of arrays of 2n nondecreasing integers in -3..3 with sum zero and equal numbers greater than zero and less than zero.at n=35A203286
• Reversal of sigma(n) equals the sum of the reversals of the divisors of n.at n=10A203615