Nanbeige-4.1-3B fine-tuned on sequelbox/Tachibana4-DeepSeek-V4-Pro. Inherits Nanbeige-4.1's built-in reasoning/thinking capability, reinforced with DeepSeek-V4-Pro coding and math traces. Capable of structured reasoning, summation/integration problems, and code generation with step-by-step explanation. 3B parameter model runnable on consumer hardware via transformers or llama.cpp.