n-Clean Rings
Let n be a positive integer. A ring R is called n-clean if every element of R can be written as a sum of an idempotent and n units in R. The class of n-clean rings contains clean rings and (S,n)-rings (i.e., every element is a sum of no more than n units). In this paper, we investigate some properties on n-clean rings. There exists a clean and (S,3)-ring which is not an (S,2)-ring. If R is a ring satisfying (SI), then the polynomial ring R[x] is not n-clean for any positive integer n. An example shows that for any positive integer n> 1, there exists a non n-clean ring R such that the 2× 2 matrix ring M2(R) over R is n-clean.
2016 ◽
Vol 15
(08)
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pp. 1650148
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2017 ◽
Vol 16
(04)
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pp. 1750073
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2004 ◽
Vol 70
(2)
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pp. 279-282
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2015 ◽
Vol 14
(06)
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pp. 1550094
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1988 ◽
Vol 110
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pp. 113-128
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2014 ◽
Vol 13
(06)
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pp. 1450009
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