Emirp primes: Difference between revisions

=={{header|R}}==

<lang rsplus>

library(gmp)

emirp <- function(start = 1, end = Inf, howmany = Inf, ignore = 0) {

count <- 0

p <- start

while (count<howmany+ignore && p <= end) {

p <- nextprime(p)

p_reverse <- as.bigz(paste0(rev(unlist(strsplit(as.character(p), ""))), collapse = ""))

if (p != p_reverse && isprime(p_reverse) > 0) {

if (count >= ignore) cat(as.character(p)," ",sep="")

count <- count + 1

}

}

cat("\n")

}

cat("First 20 emirps: ")

emirp(howmany = 20)

cat("Emirps between 7700 and 8000: ")

emirp(start = 7700, end = 8000)

cat("The 10000th emirp: ")

emirp(ignore = 9999, howmany = 1)

</lang>

{{out}}

<pre>

First 20 emirps: 13 17 31 37 71 73 79 97 107 113 149 157 167 179 199 311 337 347 359 389

Emirps between 7700 and 8000: 7717 7757 7817 7841 7867 7879 7901 7927 7949 7951 7963

The 10000th emirp: 948349

</pre>