2, 5, 28, 257, ?

M4maths Previous Puzzles

04 Feb 2012 What will be the next number?

2, 5, 28, 257, ?

OPtion

1) 326
2) 524
3) 543
4) 645
5) 756
6) 1025
7) 2258
8) 3126
9) 4534
10) none of these

Solution

1+1, 2^2+1, 3^3+1, 4^4+1, 5^5+1
= 3126

Correct Option: 8 Best Solution (17)

Gowtham   12 years AGO

Series Deduction as follows:
2=(1^1)+1;
5=(2^2)+1;
28=(3^3)+1;
257=(4^4)+1;
3126=(5^5)+1.

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arunraj   12 years AGO

Logic : N power n + 1

1 power 1 is 1 +1 =2
2 power 2 is 4 +1 =5
3 power 3 is 27 +1 =28
4 power 4 is 256 +1 =257
SO next no
5 power 5 is 3125 +1 =3126

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Shiv Kumar   12 years AGO

Series is N^N+1

1) 1^1+1 =2
2) 2^2+1 =5
3) 3^3+1 =28
4) 4^4+1 =257
5) 5^5+1 = 3126

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Abhishek Divakar   12 years AGO

sequence is
a(n)=(n^n)+1
a(1)=(1^1)+1 = 2
a(2)=(2^2)+1 = 5
a(3)=(3^3)+1 = 28
a(4)=(4^4)+1 = 257
a(5)=(5^5)+1 = 3126

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saurabh middha   12 years AGO

there is a sequence.
1^1+1,2^2+1,3^3+1,4^4+1,5^5+1,6^6+1....
1+1,4+1,27+1,256+1,3125+1,46656+1...
2,5,28,157,3126,46657....

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Pratik Goyal   12 years AGO

2=1+1
5=2*2+1
28=3*3*3+1
257=4*4*4*4+1
then next is 5*5*5*5*5+1=3126

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Sreenivasa Chowdary Nellore   12 years AGO

IT IS (1^1)+1, (2^2)+1, (3^3)+1, (4^4)+1

HENCE NEXT TERM SHOULD BE (5^5)+1

HENCE IT SHOULD BE 3125+1 = 3126
WISH YOU GOOD LUCK

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Reck   12 years AGO

rule:n^n+1
1^1+1=2
2^2+1=5
3^3+1=28
4^4+1=257
5^5+1=3126

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Veedarp   12 years AGO

(n^n)+1

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laxmi prasanna   12 years AGO

1^1+1, 2^2+1,3^3+1,4^4+1,5^5+1
that is 5^5+1=3126

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shailu   12 years AGO

ans is 312 bcoz series is 1pow1 +1=2,2pow2+1=5 ,3pow3+1=25 4po4+1=257, 5pow5+1=3126

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vetri   12 years AGO

(1^2) + 1 = 2
(2^2) + 2 = 5
(3^3) + 3 = 28
(4^4) + 4 = 257
so
(5^5) + 5 = 3126

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ashokkumar   12 years AGO

2=1^1+1=1+1=2
5=2^2+1=4+1=5
28=3^3+1=27+1=28
257=4^4+1=256+1=257
3126=5^5+1=3125+1=3126

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Subhankar Mondal   12 years AGO

1^3+1=2,2^2+1=5,3^3+1=28,4^4+1=257,5^5+1=3126

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Arunanand T A   12 years AGO

1^1+1
2^2+1
3^3+1
==> 4^4+1

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sudeep kumar   12 years AGO

2 = 1 power 1 + 1,
5 = 2 power 2 + 1,
28 = 3 power 3 + 1,
257 = 4 power 4 + 1,
so,
3126 = 5 power 5 +1.

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Balakumaran N.A   12 years AGO

A Sierpiński number of the first kind is a number of the form . The first few are 2, 5, 28, 257, 3126, 46657, 823544, 16777217, ... Sn=n^n+1..

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