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Search: id:A130283
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| A130283 |
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Integers n>0 for which A130280(n)=0, i.e. such that there is no integer m>1 for which n(m^2-1)+1 is a square. |
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5
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OFFSET
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1,1
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COMMENT
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Are there terms > 4 in this sequence which are not odd squares (cf. A130284)?
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EXAMPLE
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a(1)=4 since 1(2^2-1)+1=2^2, 2(5^2-1)+1=7^2, 3(3^2-1)+1=5^2 but 4(m^2-1)+1 = 4m^2-3 can't be a square because the largest square < 4m^2 is (2m-1)^2 = 4m^2-4m+1 < 4m^2-3 for m>1.
a(2)=9 since for n=5,6,7,8 one has m=2,3,5,2, but 9(m^2-1)+1 = 9m^2-8 > 9m^2-11 >= 9m^2-6m+1 = (3m-1)^2 and therefore can't be a square.
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CROSSREFS
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Cf. A084702, A130280, A130284, A130288.
Adjacent sequences: A130280 A130281 A130282 this_sequence A130284 A130285 A130286
Sequence in context: A082200 A063482 A069557 this_sequence A065739 A053704 A082180
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KEYWORD
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nonn
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AUTHOR
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M. F. Hasler (Maximilian.Hasler(AT)gmail.com), May 24 2007
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