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 A121061 #13 Oct 12 2024 21:35:10 %S A121061 9,10,16,18,20,22,25,29,31,34,37,42,45,48,50,56,57,60,63,69,71,72,73, %T A121061 83,85,91,101,102,112,113,114,119,139,144,148,151,155,156,172,175,183, %U A121061 185,190,192,195,202,208,217,238,242,244,245,247,256,257,272,275,291,293 %N A121061 Numbers k such that k-th partition number A000041(k) is a 3-almost prime (A014612). %F A121061 A000041(a(n)) in A014612. %e A121061 a(1) = 9 because P(9) = 30 = 2 * 3 * 5. %e A121061 a(2) = 10 because P(10) = 42 = 2 * 3 * 7. %e A121061 a(3) = 16 because P(16) = 231 = 3 * 7 * 11. %t A121061 Select[Range[300],PrimeOmega[PartitionsP[#]]==3&] (* _James C. McMahon_, Oct 12 2024 *) %Y A121061 Cf. A000041, A046063, A065728, A065729. %K A121061 easy,nonn %O A121061 1,1 %A A121061 _Jonathan Vos Post_, Aug 09 2006 %E A121061 112 and 113 inserted by _R. J. Mathar_, Dec 22 2010