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A125499 Deficient even numbers. 4
2, 4, 8, 10, 14, 16, 22, 26, 32, 34, 38, 44, 46, 50, 52, 58, 62, 64, 68, 74, 76, 82, 86, 92, 94, 98, 106, 110, 116, 118, 122, 124, 128, 130, 134, 136, 142, 146, 148, 152, 154, 158, 164, 166, 170, 172, 178, 182, 184, 188, 190, 194, 202, 206, 212, 214, 218, 226, 230 (list; graph; refs; listen; history; text; internal format)
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

CROSSREFS

Cf. A005100 = deficient numbers.

Sequence in context: A010069 A226872 A132895 * A240092 A153974 A189670

Adjacent sequences:  A125496 A125497 A125498 * A125500 A125501 A125502

KEYWORD

nonn

AUTHOR

Tanya Khovanova, Dec 27 2006

EXTENSIONS

More terms from Emeric Deutsch, Jan 01 2007

STATUS

approved

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Last modified March 27 01:05 EDT 2017. Contains 284141 sequences.