A045477 Aliquot sequence starting at 840 (reaches 1 at 747th term).

840, 2040, 4440, 9240, 25320, 51000, 117480, 271320, 765480, 1531320, 3721800, 7817640, 15635640, 32899560, 65799480, 139098120, 349027320, 699333000, 1597611000, 3386944680, 9543610200, 20041583280

Offset

0,1

References

A. W. P. Guy and R. K. Guy, A record aliquot sequence, pp. 557-559 of Mathematics of Computation 1943-1993 (Vancouver, 1993), Proc. Symp. Appl. Math., Vol. 48, Amer. Math. Soc. 1994.

Links

T. D. Noe, Table of n, a(n) for n = 0..748

Christophe CLAVIER, Aliquot Sequences

Formula

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

Mathematica

FixedPointList[If[# > 0, DivisorSigma[1, #] - #, 0]&, 840] // Most (* Jean-François Alcover, Mar 28 2020 *)

Crossrefs

Sequence in context: A169827 A158402 A361421 * A232099 A005952 A260473

Adjacent sequences: A045474 A045475 A045476 * A045478 A045479 A045480

Keyword

nonn,fini,full

Author

N. J. A. Sloane

Status

approved