A pyramid stack of soup cans is arranged in the following fashion: Layer1 has 1 can, Layer 2 has 3 cans, Layer 3 has 6 cnas, Layer 4 has 10 cans... a) Determine if the number of cans in each layer forms an arithmetic sequence? Geometric sequence? or neither?

b) Find the recursive formula tₙfor the number of cans in layer n

c) Find the nth term (explicit formula) for the number of cans in layer n

d) How many soup cans are there in the 15th layer?