Enumeration Class of Polyominoes Inscribed in James Abacus and Related ECO

Eman F. Mohommed, jalal Abd Jassim, Alina Alb Lupas, Ali A. Aubad, Eman Mohommed, Hayder R. Hashim, Hayder R. Hashim, Eman Mohommed, Ayesha Qureshi · 2026

Read Enumeration Class of Polyominoes Inscribed in James Abacus and Related ECO by Eman F. Mohommed, jalal Abd Jassim, Alina Alb Lupas, Ali A. Aubad, Eman Mohommed, Hayder R. Hashim, Hayder R. Hashim, Eman Mohommed, Ayesha Qureshi (2026) in the Tower of Babel, a free online library of public-domain works preserved in clean, searchable text. No sign-up. The full text is served as a plain-text file at a predictable URL, where text is present: https://antarctic-labs.com/tower-of-babel/pmc-13554842.txt.

Description

Mohommed and co-authors study a new class of polyominoes, shapes made of joined squares, in a paper from two thousand twenty-six. The class is defined through a counting frame called the James abacus, using chains nested inside each other. Conditions on partitions and related numbers set out which shapes belong.

The authors define two local changes that can be applied on even chains of the frame. They then derive formulas for the number of positions in each chain, the number of even chains, and the total chains. From these classes they build generating functions using a standard counting method where larger objects grow from smaller ones by local steps.

Catalog record

CREATOREman F. Mohommed, jalal Abd Jassim, Alina Alb Lupas, Ali A. Aubad, Eman Mohommed, Hayder R. Hashim, Hayder R. Hashim, Eman Mohommed, Ayesha Qureshi
YEAR2026
COLLECTIONPAPERS
FORMATTXT
FILE SIZE48 KB
VERSION1.0
LICENSECC BY 4.0
RIGHTSCC BY
SOURCEEurope PMC

Source: https://europepmc.org/articles/PMC13554842

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