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 A241092 #9 May 11 2025 19:16:11 %S A241092 0,0,0,1,0,0,1,1,1,1,1,1,2,2,3,3,3,3,4,4,5,7,7,8,9,10,10,12,13,15,17, %T A241092 19,21,25,26,29,32,35,38,42,46,51,57,62,69,76,83,90,100,107,117,127, %U A241092 139,150,165,178,195,212,231,250,273,294,319,346,373,402 %N A241092 Number of partitions p of n into distinct parts such that max(p) = 1 + 2*(number of parts of p). %F A241092 a(n) + A241086(n) + A241093(n) = A000009(n) for n >= 1. %F A241092 a(n) = A241091(n) - A241086(n) for n >= 0. %e A241092 a(12) counts these 5 partitions: 741, 732, 651, 642, 6321, 543, 5421. %t A241092 z = 30; f[n_] := f[n] = Select[IntegerPartitions[n], Max[Length /@ Split@#] == 1 &]; %t A241092 Table[Count[f[n], p_ /; Max[p] < 1 + 2*Length[p]], {n, 0, z}] (*A241086*) %t A241092 Table[Count[f[n], p_ /; Max[p] <= 1 + 2*Length[p]], {n, 0, z}](*A241091*) %t A241092 Table[Count[f[n], p_ /; Max[p] == 1 + 2*Length[p]], {n, 0, z}](*A241092*) %t A241092 Table[Count[f[n], p_ /; Max[p] >= 1 + 2*Length[p]], {n, 0, z}](*A241089*) %t A241092 Table[Count[f[n], p_ /; Max[p] > 1 + 2*Length[p]], {n, 0, z}] (*A241093*) %Y A241092 Cf. A241086, A241091, A241093, A000009. %K A241092 nonn,easy %O A241092 0,13 %A A241092 _Clark Kimberling_, Apr 18 2014