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A143721 Aliquot sequence starting at 38. 1
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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

From Michal Paulovic, Dec 31 2017: (Start)

The only integer with the sum of its proper divisors equal to 38 is 1369.

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, ...

(End)

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

LINKS

Table of n, a(n) for n=0..102.

Eric Weisstein's MathWorld, Aliquot Sequence

FORMULA

a(n+1) = A001065(a(n)). - R. J. Mathar, Oct 11 2017

From Iain Fox, Dec 31 2017: (Start)

G.f.: 38 + 22*x + 14*x^2 + 10*x^3 + 8*x^4 + 7*x^5 + x^6.

E.g.f.: (27360 + 15840*x + 5040*x^2 + 1200*x^3 + 240*x^4 + 42*x^5 + x^6)/720.

(End)

MATHEMATICA

NestList[If[# == 0, 0, DivisorSigma[1, #] - #] &, 38, 100] (* Michael De Vlieger, Dec 31 2017 *)

PROG

(PARI) x=1369; while(x, x=sigma(x)-x; if(x, print1(x ", "), print1(x ", " x ", " x ", ..."))) \\ Michal Paulovic, Dec 31 2017

CROSSREFS

Sequence in context: A160147 A033358 A033974 * A070725 A249280 A022994

Adjacent sequences:  A143718 A143719 A143720 * A143722 A143723 A143724

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 30 2008

STATUS

approved

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Last modified August 17 17:00 EDT 2019. Contains 326059 sequences. (Running on oeis4.)