perplexus.info :: Just Math : Sum Power Digit Determination

Sum Power Digit Determination (Posted on 2014-07-12)

Determine the last digit of:

1² + 2³ + 3⁴ + 4⁵ + .......+ 2014²⁰¹⁵

See The Solution Submitted by K Sengupta

Rating: 5.0000 (1 votes)

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computer solution

| Comment 1 of 4

DEFDBL A-Z

FOR n = 1 TO 2014

t = t + modpow(n, n + 1, 10000)

PRINT t MOD 10000

_clipboard$=str$(t mod 10000)

FUNCTION modpow (b, p, m)

answ = 1

FOR i = 1 TO p

answ = (answ * b) MOD m

modpow = answ

END FUNCTION

finds

4311

as the last four digits of the number, so the last digit is a 1.

Posted by Charlie on 2014-07-12 12:30:34

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