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A186644
The sum of the oex divisors of n.
2
1, 3, 4, 5, 6, 12, 8, 15, 10, 18, 12, 26, 14, 24, 24, 25, 18, 36, 20, 40, 32, 36, 24, 60, 26, 42, 40, 54, 30, 72, 32, 59, 48, 54, 48, 80, 38, 60, 56, 90, 42, 96, 44, 82, 75, 72, 48, 118, 50, 88, 72, 96, 54, 120, 72, 120, 80, 90, 60, 166, 62, 96, 101, 117, 84, 144, 68, 124, 96, 144, 72, 186, 74, 114, 119, 138, 96
OFFSET
1,2
COMMENTS
See A186643 for a definition of which divisors of n are classified as oex divisors.
LINKS
FORMULA
a(n) >= A049417(n).
MAPLE
maxval := proc(n, d) local nshf, a ; if n mod d <> 0 then 0; else nshf := n ; a := 0 ; while nshf mod d = 0 do nshf := nshf /d ; a := a+1 ; end do: a; end if; end proc:
A186644 := proc(n) a := 1 ; for d in numtheory[divisors](n) minus {1} do if type(maxval(n, d), 'odd') then a := a+d ; end if; end do: a ; end proc: # R. J. Mathar, Mar 04 2011
MATHEMATICA
Table[DivisorSum[n, # &, Or[# == 1, OddQ@ IntegerExponent[n, #]] &], {n, 77}] (* Michael De Vlieger, Nov 23 2017 *)
PROG
(PARI) a(n) = sumdiv(n, d, d*((d==1) || (valuation(n, d) % 2))); \\ Michel Marcus, Feb 06 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Feb 25 2011
EXTENSIONS
More terms from Antti Karttunen, Nov 23 2017
STATUS
approved