

A002046


Larger of amicable pair.
(Formerly M5435 N2363)


75



284, 1210, 2924, 5564, 6368, 10856, 14595, 18416, 76084, 66992, 71145, 87633, 88730, 124155, 139815, 123152, 153176, 168730, 176336, 180848, 203432, 202444, 365084, 389924, 430402, 399592, 455344, 486178, 514736, 525915, 669688, 686072
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OFFSET

1,1


COMMENTS

The elements 76084, 123152, etc. are intentionally out of numerical order so that a(n) and A002025(n) form amicable pairs.  Michael B. Porter, Apr 17 2010


REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
For additional references see A002025.


LINKS

E. B. Escott, Amicable numbers, Scripta Mathematica, 12 (1946), 6172 [Annotated scanned copy]
T. Trotter, Jr., Amicable Numbers [Warning: As of March 2018 this site appears to have been hacked. Proceed with great caution. The original content should be retrieved from the Wayback machine and added here.  N. J. A. Sloane, Mar 29 2018]


FORMULA



MAPLE

f:= proc(t) uses numtheory; local s;
s:= sigma(t)  t; s > t and sigma(s)  s = t
end proc;
Am1:= select(f, [$1..10^6]);


MATHEMATICA

amicableQ[n_] := With[{s = DivisorSigma[1, n]  n}, r = n != s && n == DivisorSigma[1, s]  s; If[r, mate[n] = s; True, False]]; mate /@ Select[ Range[lim], amicableQ[#] && # < mate[#] &] (* JeanFrançois Alcover, Sep 20 2011 *)


PROG

(PARI) aliquot(n)=sigma(n)n
isA002046(n)={local(a); a=aliquot(n); a<n && aliquot(a)==n} \\ Michael B. Porter, Apr 17 2010


CROSSREFS



KEYWORD

nonn,nice


AUTHOR



EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Oct 25 2000


STATUS

approved



