-1530240

Appears in sequences

• a(n) = 1*2*3*4*5 - 6*7*8*9*10 + 11*12*13*14*15 - ... + (up to n).at n=19A319545
• a(n) = 5*4*3*2*1 - 10*9*8*7*6 + 15*14*13*12*11 - 20*19*18*17*16 + ... - (up to the n-th term).at n=19A319888