This sequence has generating function

(if we include
for a moment)
Recall that for
, we have

Take the derivative to get


Take the derivative again:


Take the derivative one more time:


so we have

Answer:
11
Step-by-step explanation:
The lines on the outside simply means "absolute value". This just takes any negative number and makes it positive. In this case, 15-4 is already positive so the answer is just positive 11.
Answer:
Step-by-step explanation:
The numbers in the ratio add up to 10. So divide 250 by 10. One part is £25. Multiply by the given numbers: 3x25=75. 6x25=150. 1x25=25. So you have £75:£150:£25.
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