program to print bell triangle

python_programs/bell_number.py

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+#program to print bell number
+
+#Bell Number:-Let S(n, k) be total number of partitions of n elements into k sets. The value of n’th Bell Number is sum of S(n, k) for k = 1 to n. Value of S(n, k) can be defined recursively as, S(n+1, k) = k*S(n, k) + S(n, k-1)
+
+#The code to print the bell triangle is as follows-
+
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+
+n=int(input("enter the number of bell"))     #taking value from the user
+
+bell=0 #initialising bell to 'zero'
+
+k=0    #initialising k to 'zero'
+
+for i in range(0,n):
+
+    for j in range(0,i+1):
+
+        if j==0 and i>0:
+
+            print(bell,'',end='')        #printing first number of each line
+
+        else:
+
+            k=(i**2)+1+bell              #to generate other numbers of line
+
+            print(k,'',end='')           #printing other number in lines
+
+            bell=k                       #updating value of bell 
+
+    print('\n')                          #for moving into next lines           
+
+print("last number of bell is",bell)    
+
+