Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Apr 06 2020 20:28:52
%S 0,0,1,1,2,3,5,7,9,13,20,28,34,46,64,89,107,144,183,247,295,391,491,
%T 647,747,974,1200,1552,1815,2320,2778,3541,4104,5180,6191,7775,8913,
%U 11129,13178,16351,18754,23141,27024,33233,38036,46535,54202,66012,74903
%N Number of partitions p of n such that (sum of parts with multiplicity 1) < (sum of all other parts).
%F a(n) + A240452(n) = A000041(n) for n >= 0.
%e a(6) counts these 5 partitions: 33, 222, 2211, 21111, 111111.
%t z = 30; p[n_] := p[n] = IntegerPartitions[n]; f[p_] := f[p] = First[Transpose[p]];
%t ColumnForm[t = Table[Select[p[n], 2 Total[f[Select[#, Last[#] == 1 &] /. {} -> {{0, 0}}]] &[Tally[#]] < n &], {n, 0, z}]] (* shows the partitions *)
%t Map[Length, t] (* A240448 *)
%t ColumnForm[t = Table[Select[p[n], 2 Total[f[Select[#, Last[#] == 1 &] /. {} -> {{0, 0}}]] &[Tally[#]] <= n &], {n, 0, z}]] (* shows the partitions *)
%t Map[Length, t] (* A240449 *)
%t ColumnForm[t = Table[Select[p[n], 2 Total[f[Select[#, Last[#] == 1 &] /. {} -> {{0, 0}}]] &[Tally[#]] == n &], {n, 0, z}]] (* shows the partitions *)
%t Map[Length, t] (* A240447 with alternating 0's *)
%t ColumnForm[t = Table[Select[p[n], 2 Total[f[Select[#, Last[#] == 1 &] /. {} -> {{0, 0}}]] &[Tally[#]] > n &], {n, 0, z}]] (* shows the partitions *)
%t Map[Length, t] (* A240451 *)
%t ColumnForm[t = Table[Select[p[n], 2 Total[f[Select[#, Last[#] == 1 &] /. {} -> {{0, 0}}]] &[Tally[#]] >= n &], {n, 0, z}]] (* shows the partitions *)
%t Map[Length, t] (* A240452 *)
%t (* _Peter J. C. Moses_, Apr 02 2014 *)
%Y Cf. A240449, A240447, A240451, A240452, A000041.
%K nonn,easy
%O 0,5
%A _Clark Kimberling_, Apr 05 2014