Abstract
This paper presents a generalized algebraic derivation for finite sum identities within the Annamalai Combinatorial System, extending the conventional boundary of combinatorial geometric series to accommodate arbitrary starting indices. While traditional methods rely on mathematical induction, this approach utilizes series decomposition and the Cauchy product of generating functions to establish a robust closed-form expression. A key finding of this derivation is that the resulting finite closed-form expression is a rational function that remains defined for all values of x except one, providing mathematical stability beyond typical convergence intervals. The derivation rigorously accounts for truncation by evaluating the remainder term through index shifting and the substitution of sub-generating functions. By providing a precise mathematical bridge between truncated segments and infinite series, this generalized rational-form identity offers significant computational efficiency for stochastic network optimization, high-dimensional traffic analysis, and real-time algorithm execution in hardware-based architectures.



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