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A066191 Numbers n such that the sum of the odd aliquot parts of n divides n. 2
2, 3, 4, 5, 7, 8, 11, 12, 13, 16, 17, 19, 23, 24, 29, 31, 32, 37, 41, 43, 47, 48, 53, 56, 59, 61, 64, 67, 71, 73, 79, 83, 89, 96, 97, 101, 103, 107, 109, 112, 113, 120, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 192, 193, 197, 199, 211, 223 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n=1..1000

EXAMPLE

12 is in the sequence because the odd aliquot parts of 12 are {1,3} and their sum divides 12.

MAPLE

with(numtheory):soa:=proc(n) local div, s, j: div:=convert(divisors(n), list): s:=0: for j from 1 to nops(div)-1 do if div[j] mod 2=1 then s:=s+div[j] else s:=s: fi: od: end: p:=proc(n) if type(n/soa(n), integer)=true then n else fi end: seq(p(n), n=1..240); # Emeric Deutsch, Feb 26 2005

MATHEMATICA

Do[ d = Drop[ Divisors[ n ], -1 ]; l = Length[ d ]; od = 1; k = 2; While[ k <= l, If[ OddQ[ d[ [ k ] ] ], od = od + d[ [ k ] ] ]; k++ ]; If[ IntegerQ[ n/od ], Print[ n ] ], {n, 2, 200} ]

PROG

(PARI) { n=0; for (m=2, 10^9, d=divisors(m); s=1; for (i=2, numdiv(m) - 1, if (d[i]%2, s += d[i])); if (s > 0 && m%s == 0, write("b066191.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Feb 05 2010

(PARI) isok(n) = !(n % sumdiv(n, d, d*(d%2)*(d!=n))); \\ Michel Marcus, Apr 06 2015

CROSSREFS

Sequence in context: A100289 A255130 A054021 * A166159 A169693 A180121

Adjacent sequences:  A066188 A066189 A066190 * A066192 A066193 A066194

KEYWORD

nonn,easy

AUTHOR

Robert G. Wilson v, Dec 15 2001

EXTENSIONS

More terms from Emeric Deutsch, Feb 26 2005

STATUS

approved

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Last modified April 13 02:47 EDT 2021. Contains 342934 sequences. (Running on oeis4.)