A compound that gives a positive iodoform test is :

Alcohols and ketones with a ${\mathrm{CH}}_3\mathrm{CO}-$ (methyl ketone) group are found using the iodoform test.
When a substance containing methyl ketone combines with iodine in the presence of a base, the result is haloform, a precipitate that is yellow in colour.

You may write pentanone as ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2(\mathrm{C}=\mathrm{O}){\mathrm{HCH}}_3$

containing a single methyl ketone group.
As a result, the iodoform test may be positive.