

A292981


Larger of biunitary amicable pair.


7



126, 846, 1260, 3952, 5382, 8460, 6368, 8496, 13808, 10856, 14595, 17700, 51952, 49308, 53820, 83142, 62700, 71145, 73962, 97712, 107550, 88730, 108224, 131100, 153176, 168730, 196650, 203432, 195408, 287600, 309776, 306612, 365700, 332528, 399592, 419800
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OFFSET

1,1


COMMENTS

Analogous to amicable numbers with biunitary sigma (A188999) instead of sigma (A000203).
Hagis found all the biunitary amicable pairs with smaller members below 10^6.
The smaller members are in A292980.
The terms are ordered according to their lesser counterparts.


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..6368 (all terms with lesser member below 2*10^11, from David Moews' site).
Peter Hagis, Jr., Biunitary amicable and multiperfect numbers, Fibonacci Quarterly, Vol. 25, No. 2 (1987), pp. 144150.
David Moews, Perfect, amicable and sociable numbers.


EXAMPLE

3952 is in the sequence since A188999(3608)  3608 = 3952 and A188999(3952)  3952 = 3608.


MATHEMATICA

fun[p_, e_]:=If[Mod[e, 2]==1, (p^(e+1)1)/(p1), (p^(e+1)1)/(p1)p^(e/2)];
bsigma[n_] := If[n==1, 1, Times @@ (fun @@@ FactorInteger[n])]; Do[s = bsigma[n]; If[s > 2 n && bsigma[s  n] == s, Print[sn]], {n, 1, 10000}] (* Amiram Eldar, Sep 29 2018 *)


CROSSREFS

Cf. A002046, A188999, A292980.
Sequence in context: A107658 A181254 A004008 * A126170 A324709 A342307
Adjacent sequences: A292978 A292979 A292980 * A292982 A292983 A292984


KEYWORD

nonn


AUTHOR

Amiram Eldar, Sep 27 2017


STATUS

approved



