Reminder Problem (Self-Made)

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Phlembac Adib Hasan
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Reminder Problem (Self-Made)

Unread post by Phlembac Adib Hasan » Wed Apr 18, 2012 10:21 am

($10000^{th}$ post)A sequence is defined in this way:
\[a_0=3,a_1=7,a_n=(a_{n-1})^{n^n}+(a_{n-2})^{n^n}\; \; \; \text {for }n\ge 2\]Find the reminder if $a_{200000}$ is divided by $4$.

(Edited for correcting the spellings,not to change the problem.Actually I am not so good in English and also in typing.)
Last edited by Phlembac Adib Hasan on Wed Apr 18, 2012 10:38 am, edited 1 time in total.
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sourav das
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Re: Reminder Problem (Self-Made)

Unread post by sourav das » Wed Apr 18, 2012 10:28 am

Phlembac Adib Hasan wrote:($10000^{th}$ post)A sequence is defines in this way:
\[a_0=3,a_1=7,a_n=(a_{n-1})^{n^n}+(a_{n-2})^{n^n}\; \; \; \text {for }n\ge 2\]Find the reminder if $a_{200000}$ is divided by $4$.
Please clear the statement. What is divisible by 4 and remainder of what?
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Phlembac Adib Hasan
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Re: Reminder Problem (Self-Made)

Unread post by Phlembac Adib Hasan » Wed Apr 18, 2012 10:33 am

sourav das wrote:
Phlembac Adib Hasan wrote:($10000^{th}$ post)A sequence is defines in this way:
\[a_0=3,a_1=7,a_n=(a_{n-1})^{n^n}+(a_{n-2})^{n^n}\; \; \; \text {for }n\ge 2\]Find the reminder if $a_{200000}$ is divided by $4$.
Please clear the statement. What is divisible by 4 and remainder of what?
$a_{200000}\equiv ?(mod\; 4)$
Actually I chose $200000$ at random.I can choose anything else.Like $a_{124563}\equiv ?(mod\; 4)$.
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Re: Reminder Problem (Self-Made)

Unread post by *Mahi* » Wed Apr 18, 2012 9:57 pm

$a_6 \equiv 1 \pmod {4}$, $a_7 \equiv 1 \pmod 4$ and $a_8 \equiv 2 \pmod 4$. This with the fact $1^x \equiv 1 \pmod 4$ and $2^{k} \equiv 0 \pmod 4$ for $k>1$ gives the solution.
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