OFFSET
1,1
LINKS
R. J. Mathar, Table of n, a(n) for n = 1..3375
EXAMPLE
22 is in the sequence because it is even and its sum of divisors 1+2+11+22=36 is less than 2*22.
MAPLE
with(numtheory): a:=proc(n) if sigma(n)<2*n and n mod 2 = 0 then n else fi end: seq(a(n), n=1..290); # Emeric Deutsch, Jan 01 2007
isA005100 := proc(n) if numtheory[sigma](n) < 2*n then RETURN(true) ; else RETURN(false) ; fi ; end : for n from 2 to 800 by 2 do if isA005100(n) then printf("%d, ", n) ; fi ; od ; # R. J. Mathar, Jan 07 2007
MATHEMATICA
Select[Range[2, 250, 2], DivisorSigma[1, #]<2#&] (* Harvey P. Dale, Apr 04 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Tanya Khovanova, Dec 27 2006
EXTENSIONS
More terms from Emeric Deutsch, Jan 01 2007
STATUS
approved