diff --git a/project_euler/problem_164/__init__.py b/project_euler/problem_164/__init__.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/project_euler/problem_164/sol1.py b/project_euler/problem_164/sol1.py
new file mode 100644
index 000000000000..5387c89bd757
--- /dev/null
+++ b/project_euler/problem_164/sol1.py
@@ -0,0 +1,65 @@
+"""
+Project Euler Problem 164: https://projecteuler.net/problem=164
+
+Three Consecutive Digital Sum Limit
+
+How many 20 digit numbers n (without any leading zero) exist such that no three
+consecutive digits of n have a sum greater than 9?
+
+Brute-force recursive solution with caching of intermediate results.
+"""
+
+
+def solve(
+    digit: int, prev1: int, prev2: int, sum_max: int, first: bool, cache: dict[str, int]
+) -> int:
+    """
+    Solve for remaining 'digit' digits, with previous 'prev1' digit, and
+    previous-previous 'prev2' digit, total sum of 'sum_max'.
+    Pass around 'cache' to store/reuse intermediate results.
+
+    >>> solve(digit=1, prev1=0, prev2=0, sum_max=9, first=True, cache={})
+    9
+    >>> solve(digit=1, prev1=0, prev2=0, sum_max=9, first=False, cache={})
+    10
+    """
+    if digit == 0:
+        return 1
+
+    cache_str = f"{digit},{prev1},{prev2}"
+    if cache_str in cache:
+        return cache[cache_str]
+
+    comb = 0
+    for curr in range(sum_max - prev1 - prev2 + 1):
+        if first and curr == 0:
+            continue
+
+        comb += solve(
+            digit=digit - 1,
+            prev1=curr,
+            prev2=prev1,
+            sum_max=sum_max,
+            first=False,
+            cache=cache,
+        )
+
+    cache[cache_str] = comb
+    return comb
+
+
+def solution(n_digits: int = 20) -> int:
+    """
+    Solves the problem for n_digits number of digits.
+
+    >>> solution(2)
+    45
+    >>> solution(10)
+    21838806
+    """
+    cache: dict[str, int] = {}
+    return solve(digit=n_digits, prev1=0, prev2=0, sum_max=9, first=True, cache=cache)
+
+
+if __name__ == "__main__":
+    print(f"{solution(10) = }")
diff --git a/project_euler/problem_190/__init__.py b/project_euler/problem_190/__init__.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/project_euler/problem_190/sol1.py b/project_euler/problem_190/sol1.py
new file mode 100644
index 000000000000..b18d45be16b4
--- /dev/null
+++ b/project_euler/problem_190/sol1.py
@@ -0,0 +1,48 @@
+"""
+Project Euler Problem 190: https://projecteuler.net/problem=190
+
+Maximising a Weighted Product
+
+Let S_m = (x_1, x_2, ..., x_m) be the m-tuple of positive real numbers with
+x_1 + x_2 + ... + x_m = m for which P_m = x_1 * x_2^2 * ... * x_m^m is maximised.
+
+For example, it can be verified that |_ P_10 _| = 4112
+(|_ _| is the integer part function).
+
+Find Sum_{m=2}^15 = |_ P_m _|.
+
+Solution:
+- Fix x_1 = m - x_2 - ... - x_m.
+- Calculate partial derivatives of P_m wrt the x_2, ..., x_m. This gives that
+  x_2 = 2 * x_1, x_3 = 3 * x_1, ..., x_m = m * x_1.
+- Calculate partial second order derivatives of P_m wrt the x_2, ..., x_m.
+  By plugging in the values from the previous step, can verify that solution is maximum.
+"""
+
+
+def solution(n: int = 15) -> int:
+    """
+    Calculate sum of |_ P_m _| for m from 2 to n.
+
+    >>> solution(2)
+    1
+    >>> solution(3)
+    2
+    >>> solution(4)
+    4
+    >>> solution(5)
+    10
+    """
+    total = 0
+    for m in range(2, n + 1):
+        x1 = 2 / (m + 1)
+        p = 1.0
+        for i in range(1, m + 1):
+            xi = i * x1
+            p *= xi**i
+        total += int(p)
+    return total
+
+
+if __name__ == "__main__":
+    print(f"{solution() = }")