Simple implementation is not exactly speedy, but concurrency helps move things along.
sub is-narcissistic(Int $n) { $n == [+] $n.comb »**» $n.chars }
my @N = lazy (0..∞).hyper.grep: *.&is-narcissistic;
@N[^25].join(' ').say;
0 1 2 3 4 5 6 7 8 9 153 370 371 407 1634 8208 9474 54748 92727 93084 548834 1741725 4210818 9800817 9926315
This version that precalculates the values for base 1000 digits, but despite the extra work ends up taking more wall-clock time than the simpler version.
sub kigits($n) {
my int $i = $n;
my int $b = 1000;
gather while $i {
take $i % $b;
$i = $i div $b;
}
}
for (1..*) -> $d {
my @t = 0..9 X** $d;
my @table = @t X+ @t X+ @t;
sub is-narcissistic(\n) { n == [+] @table[kigits(n)] };
state $l = 2;
FIRST say "1\t0";
say $l++, "\t", $_ if .&is-narcissistic for 10**($d-1) ..^ 10**$d;
last if $l > 25
};
1 0
2 1
3 2
4 3
5 4
6 5
7 6
8 7
9 8
10 9
11 153
12 370
13 371
14 407
15 1634
16 8208
17 9474
18 54748
19 92727
20 93084
21 548834
22 1741725
23 4210818
24 9800817
25 9926315