what proportion of positive integers have exactly N pairs of consecutive integer factors?












3












$begingroup$


This is a followon to this question, which asked for the proportion of integers that have (any) consecutive integer factors.



Now, what proportion has exactly one pair? Since every odd number is = (2*n+1), we have to reject any integer K with factors 2, n, (2n+1). It looks as though there will be some ugly formula that starts with {2,n} and disallows (2n+1) ... and , when 2^j is a factor of n, disallows 2^(j+1) as a factor of K.



So, as a followon, I'll leave the general case as well: what proportion of positive integers has exactly N pairs of consecutive factors?










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$endgroup$












  • $begingroup$
    Clearly deserves a vote.
    $endgroup$
    – marty cohen
    Dec 14 '18 at 17:26
















3












$begingroup$


This is a followon to this question, which asked for the proportion of integers that have (any) consecutive integer factors.



Now, what proportion has exactly one pair? Since every odd number is = (2*n+1), we have to reject any integer K with factors 2, n, (2n+1). It looks as though there will be some ugly formula that starts with {2,n} and disallows (2n+1) ... and , when 2^j is a factor of n, disallows 2^(j+1) as a factor of K.



So, as a followon, I'll leave the general case as well: what proportion of positive integers has exactly N pairs of consecutive factors?










share|cite|improve this question









$endgroup$












  • $begingroup$
    Clearly deserves a vote.
    $endgroup$
    – marty cohen
    Dec 14 '18 at 17:26














3












3








3





$begingroup$


This is a followon to this question, which asked for the proportion of integers that have (any) consecutive integer factors.



Now, what proportion has exactly one pair? Since every odd number is = (2*n+1), we have to reject any integer K with factors 2, n, (2n+1). It looks as though there will be some ugly formula that starts with {2,n} and disallows (2n+1) ... and , when 2^j is a factor of n, disallows 2^(j+1) as a factor of K.



So, as a followon, I'll leave the general case as well: what proportion of positive integers has exactly N pairs of consecutive factors?










share|cite|improve this question









$endgroup$




This is a followon to this question, which asked for the proportion of integers that have (any) consecutive integer factors.



Now, what proportion has exactly one pair? Since every odd number is = (2*n+1), we have to reject any integer K with factors 2, n, (2n+1). It looks as though there will be some ugly formula that starts with {2,n} and disallows (2n+1) ... and , when 2^j is a factor of n, disallows 2^(j+1) as a factor of K.



So, as a followon, I'll leave the general case as well: what proportion of positive integers has exactly N pairs of consecutive factors?







number-theory






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 14 '18 at 15:44









Carl WitthoftCarl Witthoft

32618




32618












  • $begingroup$
    Clearly deserves a vote.
    $endgroup$
    – marty cohen
    Dec 14 '18 at 17:26


















  • $begingroup$
    Clearly deserves a vote.
    $endgroup$
    – marty cohen
    Dec 14 '18 at 17:26
















$begingroup$
Clearly deserves a vote.
$endgroup$
– marty cohen
Dec 14 '18 at 17:26




$begingroup$
Clearly deserves a vote.
$endgroup$
– marty cohen
Dec 14 '18 at 17:26










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