-33456domain: ZAppears in sequencesa(n) = 1*2*3*4 - 5*6*7*8 + 9*10*11*12 - 13*14*15*16 + ... - (up to n).at n=15A319544a(n) = 4*3*2*1 - 8*7*6*5 + 12*11*10*9 - 16*15*14*13 + ... - (up to the n-th term).at n=15A319887