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 A112643 Odd squarefree abundant numbers. 7
 15015, 19635, 21945, 23205, 25935, 26565, 31395, 33495, 33915, 35805, 39585, 41055, 42315, 42735, 45885, 47355, 49665, 50505, 51765, 54285, 55965, 58695, 61215, 64155, 68145, 70455, 72345, 77385, 80535, 82005, 83265, 84315, 91245 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Deviates from A046391 (does not contain 36465, 40755 for example). LINKS Donovan Johnson, Table of n, a(n) for n = 1..10000 FORMULA A087248 INTERSECT A005408. EXAMPLE 199815 = 3 * 5 * 7 * 11 * 173, with 32 divisors adding up to 400896 = 2 * 199815 + 1266. MAPLE # see A087248 for the additional code isA112643 := proc(n)     isA087248(n) and type(n, 'odd') ; end proc: for n from 1 do     if isA112643(n) then         print(n);     end if; end do: # R. J. Mathar, Nov 10 2014 MATHEMATICA ta = {{0}}; Do[g = n; s = DivisorSigma[1, n] - 2 * n; If[Greater[s, 0] && Equal[Abs[MoebiusMu[n]], 1] && !Equal[Mod[n, 2], 0], Print[n, PrimeFactorList[n], s]; ta = Append[ta, n]], {n, 1, 200000}]; {ta = Delete[ta, 1], g}(* Elemer *) Select[Range[1, 99999, 2], MoebiusMu[#] != 0 && DivisorSigma[1, #] > 2 # &] (* Alonso del Arte, Nov 11 2017 *) PROG (PARI) is(n)=if(n%2==0, return(0)); my(f=factor(n)); sigma(f)>2*n && vecmax(f[, 2])==1 \\ Charles R Greathouse IV, Feb 21 2017 CROSSREFS Cf. A087248, A046391. Sequence in context: A165614 A104875 A046391 * A129485 A249263 A294026 Adjacent sequences:  A112640 A112641 A112642 * A112644 A112645 A112646 KEYWORD nonn AUTHOR Labos Elemer, Sep 20 2005 STATUS approved

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Last modified March 22 04:32 EDT 2019. Contains 321406 sequences. (Running on oeis4.)