"Rory Winston" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> (If you're wondering, this is a Project Euler question :))
>
> If I wanted to calculate the sum of the digits in the decimal
> representation
> of 2^1000, what would be a good way to go about that?
Try this:
> library(gmp)
> for (N in c(10,16,32,100,1000))
+ {
+ s <- as.character(pow.bigz(2,N))
+ t <- as.numeric(unlist(strsplit(s,"")))
+ cat(N, s, sum(t), "\n")
+ }
10 1024 7
16 65536 25
32 4294967296 58
100 1267650600228229401496703205376 115
1000
10715086071862673209484250490600018105614048117055336074437503883703510511249361224931983788156958581275946729175531468251871452856923140435984577574698574803934567774824230985421074605062371141877954182153046474983581941267398767559165543946077062914571196477686542167660429831652624386837205668069376
1366
The first few can be verified manually.
--
efg
Earl F. Glynn
Bioinformatics
Stowers Institute for Medical Research
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