Data update

Task/Arithmetic-derivative/SETL/arithmetic-derivative.setl

@@ -0,0 +1,25 @@
+program arithmetic_derivative;
+    loop for n in [-99..100] do
+        nprint(lpad(str lagarias(n), 6));
+        if (col +:= 1) mod 10 = 0 then
+            print;
+        end if;
+    end loop;
+
+    loop for m in [1..20] do
+        nprint("D(10^" + lpad(str m, 2) + ") / 7 = ");
+        print(lagarias(10**m) div 7);
+    end loop;
+
+    proc lagarias(n);
+        return if n<0 then
+            -lagarias(-n)
+        elseif n in {0,1} then
+            0
+        elseif forall d in {2..floor sqrt n} | n mod d /= 0 then
+            1
+        else
+            (n div d)*lagarias(d) + d*lagarias(n div d)
+        end;
+    end proc;
+end program;