Larn

Larn may refer to:

See also

Larn (video game)

Larn is a roguelike computer game authored by Noah Morgan in 1986 for the UNIX operating system. Morgan's original version of Larn remains part of the NetBSD games collection.

Larn is one of the shorter roguelike games. It can take many hours and tens or even hundreds of thousands of game turns to beat other roguelikes, such as NetHack or Ancient Domains of Mystery, but Larn can reasonably be completed in one play session.

History

Primary development of Larn halted in 1991 with version 12.3, but its open source nature has led to later variants. Developers have ported the game to such diverse operating systems as Solaris, Amiga OS, Atari TOS, and Microsoft Windows.

ULarn

In 1987, Phil Cordier modified the Larn source code to form Ultra-Larn, or more commonly, ULarn. It introduced true character classes and additional levels, weapons, etc. As with its parent, other developers have maintained and refined ULarn in the absence of its author.

Gameplay

Larn is one of the first roguelike games to feature a persistent home level—in this case, a town. In addition to the player's residence, the town offers a bank, a shop, a trading post, a school, a tax administration office, and entrances to two dungeons, one of which is a volcano.

Geometric progression

In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the common ratio. For example, the sequence 2, 6, 18, 54, ... is a geometric progression with common ratio 3. Similarly 10, 5, 2.5, 1.25, ... is a geometric sequence with common ratio 1/2.

Examples of a geometric sequence are powers r^k of a fixed number r, such as 2^k and 3^k. The general form of a geometric sequence is

where r ≠ 0 is the common ratio and a is a scale factor, equal to the sequence's start value.

Elementary properties

The n-th term of a geometric sequence with initial value a and common ratio r is given by

Such a geometric sequence also follows the recursive relation

Generally, to check whether a given sequence is geometric, one simply checks whether successive entries in the sequence all have the same ratio.

The common ratio of a geometric sequence may be negative, resulting in an alternating sequence, with numbers switching from positive to negative and back. For instance