This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A186644 #18 Nov 23 2017 20:20:44 %S A186644 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, %T A186644 42,40,54,30,72,32,59,48,54,48,80,38,60,56,90,42,96,44,82,75,72,48, %U A186644 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 %N A186644 The sum of the oex divisors of n. %C A186644 See A186643 for a definition of which divisors of n are classified as oex divisors. %H A186644 Antti Karttunen, <a href="/A186644/b186644.txt">Table of n, a(n) for n = 1..16384</a> %F A186644 a(n) >= A049417(n). %p A186644 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: %p A186644 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 %t A186644 Table[DivisorSum[n, # &, Or[# == 1, OddQ@ IntegerExponent[n, #]] &], {n, 77}] (* _Michael De Vlieger_, Nov 23 2017 *) %o A186644 (PARI) a(n) = sumdiv(n, d, d*((d==1) || (valuation(n, d) % 2))); \\ _Michel Marcus_, Feb 06 2016 %Y A186644 Cf. A186643, A000203, A049417, A050376. %K A186644 nonn %O A186644 1,2 %A A186644 _Vladimir Shevelev_, Feb 25 2011 %E A186644 More terms from _Antti Karttunen_, Nov 23 2017