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Numbers n such that 3n is a partition number.
11

%I #29 Jan 18 2014 16:16:54

%S 1,5,10,14,45,77,99,209,264,334,525,812,1868,2783,3381,4961,10395,

%T 12446,14861,21087,35186,49091,79981,93863,109977,204718,373835,

%U 501833,1029245,1362656,1565735,2706088,5265492,14702703,44410310,80421793,101600455,128092112,143716463,226634401,354714817,947313500,1054375784

%N Numbers n such that 3n is a partition number.

%C Is this sequence infinite? Klarreich writes: no one has proved whether there are infinitely many partition numbers divisible by 3 (see _Jonathan Vos Post_'s comment in A000041 and A087183). - _Omar E. Pol_, Jan 14 2014

%F a(j) = A087183(j)/3.

%t Select[PartitionsP[Range[300]], Mod[#, 3] == 0 &]/3 (* _Omar E. Pol_, May 07 2013 *)

%Y Cf. A000041, A087183, A213179, A216258, A217725, A217726, A222175, A222178, A222179, A225317, A225323.

%K nonn

%O 1,2

%A _Omar E. Pol_, Jan 08 2013

%E a(35)-a(43) from _R. J. Mathar_, May 05 2013