Первый регуляризованный след оператора двукратного дифференцирования на проколотом отрезке

There are found the formulas of the first regularized trace (of the type of abstract Gel'fand–Levitan formula) of the two-fold differentiation operator in a punctured segment. Proof of the main result is given by the method of contour integration with corrections of the analytic perturbation theory. Some well-known trace formulas are generalized.