Which of these formulas models thisarithmetic sequence

A homeland for the Jewish people is an idea rooted in Jewish culture and religion. In the early 19th century, the Napoleonic Wars led to the idea of Jewish emancipation.[1] This unleashed a number of religious and secular cultural streams and political philosophies among the Jews in Europe, covering everything from Marxism to Chassidism. Among these movements was Zionism as promoted by Theodore Herzl.[2] In the late 19th century, Herzl set out his vision of a Jewish state and homeland for the Jewish people in his book Der Judenstaat. Herzl was later hailed by the Zionist political parties as the founding father of the State of Israel.[3][4][5]

In the Balfour Declaration of 1917, the United Kingdom became the first world power to endorse the establishment in Palestine of a "national home for the Jewish people." The British government confirmed this commitment by accepting the British Mandate for Palestine in 1922 (along with their colonial control of the Pirate Coast, Southern Coast of Persia, Iraq and from 1922 a separate area called Transjordan, all of the Middle-Eastern territory except the French territory). The European powers mandated the creation of a Jewish homeland at the San Remo conference of 19-26 April 1920.[6] In 1948, the State of Israel was established.