Ramanujan's constant: Difference between revisions

===Direct calculation===

===Continued fractions===

{{trans|Perl 6}}

<lang perl>use strict;

use Math::AnyNum <as_dec rat>;

sub continued_fr {

my ($a, $b, $n) = (@_[0,1], $_[2] // 100);

$a->() + ($n && $b->() / continued_fr($a, $b, $n-1));

}

my $r163 = continued_fr do {my $n; sub {$n++ ? 2*12 : 12 }}, do {my $n; sub { rat 19 }}, 40;

my $pi = continued_fr do {my $n; sub {$n++ ? 1 + 2*($n-2) : 0 }}, do {my $n; sub { rat($n++ ? ($n>2 ? ($n-1)**2 : 1) : 4)}}, 140;

my $p = $pi * $r163;

my $R = 1 + $p / continued_fr do { my $n; sub { $n++ ? $p+($n+0) : 1 } }, do {my $n; sub { $n++; -1*$n*$p }}, 180;

printf "Ramanujan's constant\n%s\n", as_dec($R,58);

</lang>

{{out}}

<pre>Ramanujan's constant

262537412640768743.9999999999992500725971981856888793538563</pre>