Data commit

Task/Van-Eck-sequence/Perl/van-eck-sequence.pl

@@ -0,0 +1,36 @@
+use strict;
+use warnings;
+use feature 'say';
+
+sub van_eck {
+    my($init,$max) = @_;
+    my(%v,$k);
+    my @V = my $i = $init;
+    for (1..$max) {
+        $k++;
+        my $t  = $v{$i} ? $k - $v{$i} : 0;
+        $v{$i} = $k;
+        push @V, $i = $t;
+    }
+    @V;
+}
+
+for (
+    ['A181391', 0],
+    ['A171911', 1],
+    ['A171912', 2],
+    ['A171913', 3],
+    ['A171914', 4],
+    ['A171915', 5],
+    ['A171916', 6],
+    ['A171917', 7],
+    ['A171918', 8],
+) {
+    my($seq, $start) = @$_;
+    my @seq = van_eck($start,1000);
+    say <<~"END";
+    Van Eck sequence OEIS:$seq; with the first term: $start
+            First 10 terms: @{[@seq[0  ..  9]]}
+    Terms 991 through 1000: @{[@seq[990..999]]}
+    END
+}