cp's OEIS Frontend

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.

A175342 Number of arithmetic progressions (where the difference between adjacent terms is either positive, 0, or negative) of positive integers that sum to n.

This page as a plain text file.
%I A175342 #29 Sep 29 2019 02:05:34
%S A175342 1,2,4,5,6,10,8,10,15,14,12,22,14,18,28,21,18,34,20,28,38,28,24,46,31,
%T A175342 32,48,38,30,62,32,40,58,42,46,73,38,46,68,58,42,84,44,56,90,56,48,94,
%U A175342 55,70,90,66,54,106,70,74,100,70,60,130,62,74,118,81,82,130,68,84,120
%N A175342 Number of arithmetic progressions (where the difference between adjacent terms is either positive, 0, or negative) of positive integers that sum to n.
%H A175342 Lars Blomberg, <a href="/A175342/b175342.txt">Table of n, a(n) for n = 1..10000</a>
%H A175342 Lars Blomberg, <a href="/A175342/a175342.cs.txt">C# program for calculating b-file</a>.
%H A175342 Sadek Bouroubi and Nesrine Benyahia Tani, <a href="http://ftp.math.uni-rostock.de/pub/romako/heft64/bou64.pdf"> Integer partitions into arithmetic progressions</a>, Rostok. Math. Kolloq. 64 (2009), 11-16.
%H A175342 Graeme McRae, <a href="https://web.archive.org/web/20081122034835/http://2000clicks.com/MathHelp/BasicSequenceA049982.htm">Counting arithmetic sequences whose sum is n</a>.
%H A175342 Graeme McRae, <a href="/A049988/a049988.pdf">Counting arithmetic sequences whose sum is n</a> [Cached copy]
%H A175342 Augustine O. Munagi, <a href="https://eudml.org/doc/228820">Combinatorics of integer partitions in arithmetic progression</a>, Integers 10(1) (2010), 73-82.
%H A175342 Augustine O. Munagi and Temba Shonhiwa, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL11/Shonhiwa/shonhiwa13.html">On the partitions of a number into arithmetic progressions</a>, Journal of Integer Sequences 11 (2008), Article 08.5.4.
%H A175342 A. N. Pacheco Pulido, <a href="http://www.bdigital.unal.edu.co/7753/">Extensiones lineales de un poset y composiciones de números multipartitos</a>, Maestría thesis, Universidad Nacional de Colombia, 2012.
%H A175342 Wikipedia, <a href="https://en.wikipedia.org/wiki/Arithmetic_progression">Arithmetic progression</a>.
%H A175342 Gus Wiseman, <a href="/A325325/a325325.txt">Sequences counting and ranking integer partitions by the differences of their successive parts</a>.
%F A175342 a(n) = 2*A049988(n) - A000005(n).
%F A175342 G.f.: x/(1-x) + Sum_{k>=2} x^k * (1 + x^(k(k-1)/2)) / (1 - x^(k(k-1)/2)) / (1 -x^k).
%e A175342 From _Gus Wiseman_, May 15 2019: (Start)
%e A175342 The a(1) = 1 through a(8) = 10 compositions with equal differences:
%e A175342   (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
%e A175342        (11)  (12)   (13)    (14)     (15)      (16)       (17)
%e A175342              (21)   (22)    (23)     (24)      (25)       (26)
%e A175342              (111)  (31)    (32)     (33)      (34)       (35)
%e A175342                     (1111)  (41)     (42)      (43)       (44)
%e A175342                             (11111)  (51)      (52)       (53)
%e A175342                                      (123)     (61)       (62)
%e A175342                                      (222)     (1111111)  (71)
%e A175342                                      (321)                (2222)
%e A175342                                      (111111)             (11111111)
%e A175342 (End)
%t A175342 Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],SameQ@@Differences[#]&]],{n,0,15}] (* returns a(0) = 1, _Gus Wiseman_, May 15 2019*)
%Y A175342 Cf. A000005, A000079, A049980, A049981, A049982, A049983, A049986, A049987, A049988, A049989, A049990, A070211, A127938, A175327, A325328, A325407, A325545, A325546, A325547, A325548, A325557, A325558.
%K A175342 nonn
%O A175342 1,2
%A A175342 _Leroy Quet_, Apr 17 2010
%E A175342 Edited and extended by _Max Alekseyev_, May 03 2010