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A068077
Numbers n such that sigma(n)+sigma(n+1)=4n.
3
1, 38184, 458010, 776112, 65676408, 1488668112, 4414086384, 28645019964, 46696401675, 65466785748, 70619381496, 176151711072
OFFSET
1,2
COMMENTS
a(13) > 10^13. - Giovanni Resta, Jul 11 2013
MATHEMATICA
For[n=1, True, n++, If[DivisorSigma[1, n]+DivisorSigma[1, n+1]==4n, Print[n]]]
CROSSREFS
Sequence in context: A187938 A235185 A172842 * A094427 A298427 A138400
KEYWORD
more,nonn
AUTHOR
Dean Hickerson, Feb 16 2002
EXTENSIONS
a(6)-a(8) from Donovan Johnson, Jan 31 2009
a(9)-a(12) from Giovanni Resta, Jul 11 2013
STATUS
approved