Program for Print Number series without using loop

def PrintNumber(N, Original, K, flag):

print(N, end = " ")

if (N <= 0):

if(flag==0):

flag = 1

else:

flag = 0

if (N == Original and (not(flag))):

return

if (flag == True):

PrintNumber(N - K, Original, K, flag)

return

if (not(flag)):

PrintNumber(N + K, Original, K, flag);

return

N = 20

K = 6

PrintNumber(N, N, K, True)