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 A058884 #41 Jul 02 2025 16:02:00 %S A058884 -1,0,0,1,2,5,8,15,23,37,55,83,118,171,238,332,453,618,827,1107,1460, %T A058884 1922,2504,3253,4188,5380,6860,8722,11024,13895,17421,21787,27122, %U A058884 33677,41653,51390,63179,77496,94755,115600,140632,170725,206717,249804,301151,362367,435077,521439,623674,744695 %N A058884 Partial sums of the partition function (A000041), with the last term subtracted. Also the sum of the row of the character table for S_n corresponding to the partition n-1,1 for n>1. Also the sum over all partitions lambda of n of one less than the number of 1's in lambda. %C A058884 For n>=1 number of up-steps in all partitions of n (represented as weakly increasing lists), see example. - _Joerg Arndt_, Sep 03 2014 %H A058884 Andrew Howroyd, <a href="/A058884/b058884.txt">Table of n, a(n) for n = 0..1000</a> %H A058884 M. Archibald, A. Blecher, A. Knopfmacher, and M. E. Mays, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL23/Archibald/arch3.html">Inversions and Parity in Compositions of Integers</a>, J. Int. Seq., Vol. 23 (2020), Article 20.4.1. %H A058884 Anders Claesson, Atli Fannar FranklĂn, and Einar SteingrĂmsson, <a href="https://arxiv.org/abs/2305.09457">Permutations with few inversions</a>, arXiv:2305.09457 [math.CO], 2023. %H A058884 S. Heubach, A. Knopfmacher, M. E. Mays and A. Munagi, <a href="https://www.researchgate.net/publication/228671252_Inversions_in_compositions_of_integers">Inversions in Compositions of Integers</a>, Quaestiones Mathematicae 34 (2011), 187-202. %F A058884 From _Andrew Howroyd_, Apr 21 2023: (Start) %F A058884 a(n) = A000070(n-1) - A000041(n) for n > 0. %F A058884 G.f.: (2*x - 1)*P(x)/(1 - x) where P(x) is the g.f. of A000041. (End) %e A058884 a(6) = 8 because the 11 partitions of 6 %e A058884 01: [ 1 1 1 1 1 1 ] %e A058884 02: [ 1 1 1 1 2 ] %e A058884 03: [ 1 1 1 3 ] %e A058884 04: [ 1 1 2 2 ] %e A058884 05: [ 1 1 4 ] %e A058884 06: [ 1 2 3 ] %e A058884 07: [ 1 5 ] %e A058884 08: [ 2 2 2 ] %e A058884 09: [ 2 4 ] %e A058884 10: [ 3 3 ] %e A058884 11: [ 6 ] %e A058884 contain 0+1+1+1+1+2+1+0+1+0+0 = 8 up-steps. - _Joerg Arndt_, Sep 03 2014 %p A058884 a:= proc(n) uses combinat; add(numbpart(k), k=0..n-1)-numbpart(n) end: %p A058884 seq(a(n), n=0..49); %t A058884 p[n_] := IntegerPartitions[n]; l[n_] := Length[p[n]]; Table[Count[Flatten[p[n]], 1] - l[n], {n, 0, 30}] (* _Clark Kimberling_, Mar 08 2012 *) %o A058884 (PARI) a(n) = {sum(k=0, n-1, numbpart(k)) - numbpart(n)} \\ _Andrew Howroyd_, Apr 21 2023 %o A058884 (PARI) Vec((2*x - 1)/(1 - x)/eta(x + O(x^51))) \\ _Andrew Howroyd_, Apr 21 2023 %Y A058884 Cf. A000041, A000070. %Y A058884 Cf. A218074 (up-steps in partitions into distinct parts). %K A058884 sign,easy %O A058884 0,5 %A A058884 _Edward Early_, Jan 08 2001 %E A058884 More terms from _James Sellers_, Sep 28 2001