24280

Appears in sequences

• Triangle T(n,k) read by rows; given by [0,1,0,1,0,1,0,1,...] DELTA [1,0,1,1,1,2,1,3,1,4,1,5,...], where DELTA is the operator defined in A084938.at n=63A085791
• Number of (n+1)X(n+1) -10..10 symmetric matrices with every 2X2 subblock having sum zero and two, three or four distinct values.at n=2A211820
• The smaller of the lexicographically least pair (x, y) such that 0 < x < y and sigma(x) = sigma(y) = n + x + y.at n=11A285889