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A158963
Numbers n such that A160691(n)=12.
2
2993, 63254, 63792, 82213, 104728, 130811, 135767, 137994, 149813, 156335, 193041, 193776, 199879, 210805, 211672, 223315, 251970, 260321, 262337, 272797, 275037, 282223, 286055, 287700, 288132, 290011, 305784, 308918, 320597, 324168, 346165, 347376, 361103, 372074, 381698
OFFSET
1,1
COMMENTS
What is the first number n such that A160691(n) is not in the set {1,2,4,6,8,12}?
271532 is the first such number and A160691(271532)=10. - Michel Marcus, Sep 05 2017
MATHEMATICA
c[1]=1; c[n_]:=c[n]=(s=Sum[c[k], {k, n-1}]; For[m=1, DivisorSigma[0, m]!=
DivisorSigma[0, s+m], m++ ]; m); Do[If[DivisorSigma[0, c[n]]==12, Print[n]], {n, 210000}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht, May 28 2009
EXTENSIONS
More terms from Michel Marcus, Sep 05 2017
STATUS
approved