8,15,48,143,360,783,__

• It is 3^2-1, 4^2-1, 7^2-1, 12^2-1, 19^2-1, 28^2-1, 39^2-1 The difference between squares are odd no. differences of 1,3,5,7,9,11,13. So next no. Would be 39^2-1 = 1521.
• 11 years agoHelpfull: Yes(3) No(0)
• 3^2 -1 =8, now (3 plus 1) it is 4 so, 4^2 -1=15, now (4 plus 3) ,so ,7^2-1=48,now (7+5=12),so ,12^2-1=143,now (12 plus 7) ,so, 19^2-1=360, now (19 plus 9),so,28^2-1=783,now (28 plus 11),so, 39^2-1=1521.hence the answer is "1521" .besides this is series of phytogorian triplets...
• 11 years agoHelpfull: Yes(2) No(0)