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A169822
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Numbers n such that A(n+1) = A(n) + 1, where A() = A005101() are the abundant numbers.
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5
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1432, 1487, 1849, 2742, 5380, 5434, 6474, 6786, 9752, 10674, 12311, 14115, 14557, 15237, 17266, 17558, 18987, 19138, 19761, 20110, 20259, 20343, 20967, 20997, 22262, 22735, 24342, 25650, 26003, 26471, 27122, 27721, 28914, 28968, 29741
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OFFSET
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1,1
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COMMENTS
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A096399 is the main entry for this sequence.
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LINKS
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MAPLE
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with(numtheory): A:=select(n->sigma(n)>2*n, [$1..150000]):
a:=select(j->A[j+1]=A[j]+1, [$1..nops(A)-1]); # Muniru A Asiru, Jun 10 2018
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MATHEMATICA
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fQ[n_] := DivisorSigma[1, n] > 2 n; lst = {}; c = 0; k = 1; While[k < 125000, If[fQ@k, c++; If[fQ[k - 1], AppendTo[lst, c - 1]]]; k++ ]; lst (* Robert G. Wilson v, Jun 11 2010 *)
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PROG
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(GAP) A:=Filtered([1..150000], n->Sigma(n)>2*n);;
a:=Filtered([1..Length(A)-1], i->A[i+1]=A[i]+1); # Muniru A Asiru, Jun 10 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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EXTENSIONS
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STATUS
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approved
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