This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A213365 #34 May 16 2025 07:32:30 %S A213365 1,5,10,14,45,77,99,209,264,334,525,812,1868,2783,3381,4961,10395, %T A213365 12446,14861,21087,35186,49091,79981,93863,109977,204718,373835, %U A213365 501833,1029245,1362656,1565735,2706088,5265492,14702703,44410310,80421793,101600455,128092112,143716463,226634401,354714817,947313500,1054375784 %N A213365 Numbers k such that 3*k is a partition number. %C A213365 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 %H A213365 Amiram Eldar, <a href="/A213365/b213365.txt">Table of n, a(n) for n = 1..1000</a> %F A213365 a(n) = A087183(n)/3. %t A213365 Select[PartitionsP[Range[300]], Mod[#, 3] == 0 &]/3 (* _Omar E. Pol_, May 07 2013 *) %Y A213365 Cf. A000041, A087183, A213179, A216258, A217725, A217726, A222175, A222178, A222179, A225317, A225323. %K A213365 nonn %O A213365 1,2 %A A213365 _Omar E. Pol_, Jan 08 2013 %E A213365 a(35)-a(43) from _R. J. Mathar_, May 05 2013