In the sequence 1,2,2,4,8,32,256...
each term (starting from the third term) is the product of the two terms before it. For example, the seventh term is 256 , which is the product of the fifth term (8) and the sixth term (32).
This sequence can be continued forever, though the numbers very quickly grow enormous! (For example, the 14'th term is close to some estimates of the number of particles in the observable universe.)
What is the last digit of the term of the sequence
I assume he/she means the 14th term. If so, then the 14th is:
1
2
2
4
8
32
256
8192
2097152
1 7179869184
3602879 7018963968
6189700 1964269013 7449562112
2230 0745198530 6231415357 1827264836 1505980416
1 3803492693 5811275748 6951172455 4050904902 2179443407 7311032504 8447598592
This is simple pattern recognizing
the first few terms are 1, 2, 2, 4, 8, 32, 256, 8192, 2097152...
Notice how the last digits are forming a pattern, (2, 2, 4, 8, 2, 6, 2, 2, 4, 8, 2, 6, 2...
The pattern is 2 -> 2 -> 4 -> 8 -> 2 -> 6
So if the pattern repeats every 6 terms. And assuming you are trying to find the 14th term. You divide 14 by 6 and find the remainder, which is 2.
So look at the 2nd term in the pattern. which is 2.
But remember the first term is 1, so you have to count back a term
So the answer is 2
In the sequence 1,2,2,4,8,32,256...
each term (starting from the third term) is the product of the two terms before it. For example, the seventh term is 256 , which is the product of the fifth term (8) and the sixth term (32).
This sequence can be continued forever, though the numbers very quickly grow enormous! (For example, the 14'th term is close to some estimates of the number of particles in the observable universe.)
What is the last digit of the term of the sequence
a1=1a2=2a3=a2⋅a1=a12a4=a3⋅a2=a12⋅a2=a22a5=a4⋅a3=a22⋅a12=a32a6=a5⋅a4=a32⋅a32=a52a7=a6⋅a5=a52⋅a32=a82a8=a7⋅a6=a82⋅a52=a132a9=a8⋅a7=a132⋅a82=a212…
Let F are the Fibonacci number F1=1F2=1F3=2F4=3F5=4F6=5F7=13F8=21F9=34F10=55F11=89F12=144F13=233F14=377…
an=aFn−12|a2=2an=2Fn−1
If n = 14:
a14=2F14−1a14=2F13|F13=233a14=2233 The last digit of the term a142233(mod10)≡213⋅17+12(mod10)≡(213)17212(mod10)|213≡2(mod10)≡217⋅212(mod10)≡229(mod10)≡213⋅2+3(mod10)≡(213)223(mod10)|213≡2(mod10)≡22⋅23(mod10)≡25(mod10)≡32(mod10)≡2(mod10)
The last digit of the term a14 is 2