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