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A139799
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Integers k with at least one divisor d > 1 that divides (n/d)+1.
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1
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2, 6, 10, 12, 14, 15, 18, 20, 22, 24, 26, 28, 30, 33, 34, 38, 42, 44, 45, 46, 50, 51, 54, 56, 58, 60, 62, 66, 69, 70, 72, 74, 76, 78, 82, 86, 87, 90, 91, 92, 94, 95, 96, 98, 102, 105, 106, 108, 110, 114, 118, 120, 122, 123, 124, 126, 130, 132, 134, 138, 140
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OFFSET
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1,1
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COMMENTS
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Previous name: Sequence of integers n>=2 such that there is an integer k>1 with k divides n and k divides (n/k)+1.
The first square in the sequence is 1225.
First squares are 1225, 8100, 25600, 46225. - Zak Seidov, Nov 14 2012
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LINKS
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EXAMPLE
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2 is a term since 2 divides 2 and 2/2 + 1.
6 is a term since 3 divides 6 and 6/3 + 1.
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MATHEMATICA
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okQ[n_] := Sum[Divisible[n/d+1, d] // Boole, {d, Divisors[n] // Rest}] > 0;
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PROG
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(PARI) isok(n) = sumdiv(n, d, (d>1) && !(((n/d)+1) % d)) >= 1; \\ Michel Marcus, May 08 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Juan Lopez Gonzalez (e44625(AT)estudiante.uam.es), Jun 14 2008
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EXTENSIONS
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Number 37 corrected to 38 by Zak Seidov, Nov 14 2012
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STATUS
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approved
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