Data commit

Task/Jacobsthal-numbers/Go/jacobsthal-numbers.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+    "fmt"
+    "math/big"
+)
+
+func jacobsthal(n uint) *big.Int {
+    t := big.NewInt(1)
+    t.Lsh(t, n)
+    s := big.NewInt(1)
+    if n%2 != 0 {
+        s.Neg(s)
+    }
+    t.Sub(t, s)
+    return t.Div(t, big.NewInt(3))
+}
+
+func jacobsthalLucas(n uint) *big.Int {
+    t := big.NewInt(1)
+    t.Lsh(t, n)
+    a := big.NewInt(1)
+    if n%2 != 0 {
+        a.Neg(a)
+    }
+    return t.Add(t, a)
+}
+
+func main() {
+    jac := make([]*big.Int, 30)
+    fmt.Println("First 30 Jacobsthal numbers:")
+    for i := uint(0); i < 30; i++ {
+        jac[i] = jacobsthal(i)
+        fmt.Printf("%9d ", jac[i])
+        if (i+1)%5 == 0 {
+            fmt.Println()
+        }
+    }
+
+    fmt.Println("\nFirst 30 Jacobsthal-Lucas numbers:")
+    for i := uint(0); i < 30; i++ {
+        fmt.Printf("%9d ", jacobsthalLucas(i))
+        if (i+1)%5 == 0 {
+            fmt.Println()
+        }
+    }
+
+    fmt.Println("\nFirst 20 Jacobsthal oblong numbers:")
+    for i := uint(0); i < 20; i++ {
+        t := big.NewInt(0)
+        fmt.Printf("%11d ", t.Mul(jac[i], jac[i+1]))
+        if (i+1)%5 == 0 {
+            fmt.Println()
+        }
+    }
+
+    fmt.Println("\nFirst 20 Jacobsthal primes:")
+    for n, count := uint(0), 0; count < 20; n++ {
+        j := jacobsthal(n)
+        if j.ProbablyPrime(10) {
+            fmt.Println(j)
+            count++
+        }
+    }
+}