C :

#include<stdio.h>
main()
{
	int n,i,j,l=0;
	scanf("%d",&n);
	int a[100][100]={0},m=n;
	
	while(l<n)
	{
	
	for(i=l;i<n*2+1-l;i++)
	a[l][i]=m;
	for(i=1+l;i<n*2+1-l;i++)
	a[i][n*2+1-1-l]=m;
	for(i=n*2+1-2-l;i>=l;i--)
	a[n*2+1-1-l][i]=m;
	for(i=n*2+1-2-l;i>=1+l;i--)
	a[i][l]=m; 
	
 
m--;
l++;	
}
	
	for(i=0;i<n*2+1;i++)
	{
	for(j=0;j<n*2+1;j++)
	{printf("%2d",a[i][j]);}
    printf("\n");
	}
}

C++ :

#include<iostream>
using namespace std;
int main(){
	int n,i,j,s;
	cin>>n;
	int a[2*n+1][2*n+1];
	for(i=0;i<n+1;i++){
		s=n;
		for(j=0;j<n+1;j++){
			a[i][j]=s;
			if(j<i) s--;
		}
		for(j=n+1;j<2*n+1;j++){
			if(j>2*n-i) s++;
			a[i][j]=s;
		}
	}
	for(i=n+1;i<2*n+1;i++){
		s=n;
		for(j=0;j<n+1;j++){
			a[i][j]=s;
			if(j<2*n-i) s--;
		}
		for(j=n+1;j<2*n+1;j++){
			if(j>i) s++;
			a[i][j]=s;
		}
	}
	for(i=0;i<2*n+1;i++){
		for(j=0;j<2*n+1;j++) printf("%2d",a[i][j]);
		cout<<endl;
	}
}

Python :

n=int(input())
a=[[0 for i in range(2*n+1)] for j in range(2*n+1)]
k=n
n=2*n+1
for i in range(n//2+1):
    for j in range(i,n-i):
        a[i][j]=k
    for j in range(i+1,n-i):
        a[j][n-i-1]=k
    for j in range(n-i-2,i-1,-1):
        a[n-i-1][j]=k
    for j in range(n-i-2,i,-1):
        a[j][i]=k
    k=k-1
for i in range(n):
    for j in range(n):
        print("%2d"%a[i][j],end="")
    print()