Openai/69508c1f-2064-8012-8f0a-41df99edf034

This conversation was exported from ChatGPT^[1]

gpt-5-2-thinking[edit | edit source]

User: Give me all 4-digit codes such that the sum of the digits is 17 and at least one digit appears twice.[edit | edit source]

Give me all 4-digit codes such that the sum of the digits is 17 and at least one digit appears twice. Use Python to generate and validate.

Assistant:[edit | edit source]

Assistant: python[edit | edit source]

codes = []
for n in range(10000):
    s = f"{n:04d}"                 # includes leading zeros
    digits = [int(ch) for ch in s]
    if sum(digits) == 17 and len(set(digits)) < 4:   # at least one repeated digit
        codes.append(s)

=== validate ===
assert all(sum(int(ch) for ch in c) == 17 for c in codes)
assert all(len(set(c)) < 4 for c in codes)

print(len(codes))
print("\n".join(codes))

Output (276 codes):

References[edit | edit source]

↑ "4-digit codes sum 17". ChatGPT. Retrieved 2025-12-28.

[1] "4-digit codes sum 17". ChatGPT. Retrieved 2025-12-28.

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