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
KEYWORD
nonn,easy
AUTHOR
Robert G. Wilson v, Dec 15 2001
EXTENSIONS
More terms from Emeric Deutsch, Feb 26 2005
STATUS
approved