|
%I #54 Mar 29 2018 10:09:50
%S 38,22,14,10,8,7,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N Aliquot sequence starting at 38.
%C From _Michal Paulovic_, Dec 31 2017: (Start)
%C The only integer with the sum of its proper divisors equal to 38 is 1369.
%C The sequence's pattern: 6+2^5, 6+2^4, 6+2^3, 6+2^2, 6+2^1, 6+2^0, 1, 0, 0, 0, ...
%C (End)
%C Part of the larger aliquot sequence: 12135617199, 5556030801, 2107460079, 1016939121, 496646799, 231221769, 85406391, 55582041, 19742503, 1794785, 366535, 107225, 25765, 5159, 1369, 38, 22, 14, 10, 8, 7, 1, 0, ..., . - _Robert G. Wilson v_, Mar 05 2018
%H Eric Weisstein's MathWorld, <a href="http://mathworld.wolfram.com/AliquotSequence.html">Aliquot Sequence</a>
%F a(n+1) = A001065(a(n)). - _R. J. Mathar_, Oct 11 2017
%F From _Iain Fox_, Dec 31 2017: (Start)
%F G.f.: 38 + 22*x + 14*x^2 + 10*x^3 + 8*x^4 + 7*x^5 + x^6.
%F E.g.f.: (27360 + 15840*x + 5040*x^2 + 1200*x^3 + 240*x^4 + 42*x^5 + x^6)/720.
%F (End)
%t NestList[If[# == 0, 0, DivisorSigma[1, #] - #] &, 38, 100] (* _Michael De Vlieger_, Dec 31 2017 *)
%o (PARI) x=1369; while(x,x=sigma(x)-x;if(x,print1(x ", "),print1(x ", " x ", " x ", ..."))) \\ _Michal Paulovic_, Dec 31 2017
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_, Nov 30 2008
|
