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A077089 Quotients when sigma[n+1]/sigma[n] is integer. 0
3, 2, 1, 2, 1, 1, 2, 1, 1, 1, 2, 3, 1, 3, 1, 2, 1, 2, 2, 3, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 2, 2, 2, 3, 1, 2, 2, 3, 2, 2, 1, 2, 1, 2, 1, 1, 1, 1, 2, 3, 2, 2, 1, 2, 2, 1, 2, 3, 3, 1, 3, 1, 2, 2, 2, 3, 2, 1, 1, 3, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 1, 3, 3, 2, 1, 2, 1, 2, 2, 3, 1, 2, 2, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

n=1: sigma[2]/sigma[1]=3/1=3=a(1); n=14: sigma[15]/sigma[14]=24/24=1=a(2); n=5: sigma[6]/1igma[5]=12/6=2=a(3).

MATHEMATICA

Do[s=Mod[a=DivisorSigma[1, n+1], b=DivisorSigma[1, n]]; If[Equal[s, 0], Print[a/b]], {n, 1, 10000000}]

Select[#[[2]]/#[[1]]&/@Partition[DivisorSigma[1, Range[10^6]], 2, 1], IntegerQ] (* Harvey P. Dale, Dec 26 2015 *)

CROSSREFS

Cf. A000203, A002961, A067081, A077086, A077087.

Sequence in context: A306287 A016457 A181715 * A156352 A323756 A175191

Adjacent sequences:  A077086 A077087 A077088 * A077090 A077091 A077092

KEYWORD

nonn

AUTHOR

Labos Elemer, Oct 31 2002

STATUS

approved

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Last modified January 19 15:37 EST 2020. Contains 331049 sequences. (Running on oeis4.)