Initial data commit

Task/Jacobsthal-numbers/Sidef/jacobsthal-numbers.sidef

@@ -0,0 +1,19 @@
+func jacobsthal(n) {
+    lucasU(1, -2, n)
+}
+
+func lucas_jacobsthal(n) {
+    lucasV(1, -2, n)
+}
+
+say "First 30 Jacobsthal numbers:"
+say 30.of(jacobsthal)
+
+say "\nFirst 30 Jacobsthal-Lucas numbers:"
+say 30.of(lucas_jacobsthal)
+
+say "\nFirst 20 Jacobsthal oblong numbers:"
+say 21.of(jacobsthal).cons(2, {|a,b| a * b })
+
+say "\nFirst 20 Jacobsthal primes:";
+say (1..Inf -> lazy.map(jacobsthal).grep{.is_prime}.first(20))