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.

A325771 Rectangular array: row n shows the number of parts in all partitions of n that are == k (mod 2), for k = 0, 1.

Original entry on oeis.org

0, 1, 1, 2, 1, 5, 4, 8, 5, 15, 11, 24, 15, 39, 28, 58, 38, 90, 62, 130, 85, 190, 131, 268, 177, 379, 258, 522, 346, 722, 489, 974, 648, 1317, 890, 1754, 1168, 2330, 1572, 3058, 2042, 4010, 2699, 5200, 3475, 6731, 4532, 8642, 5783, 11068, 7446, 14076, 9430
Offset: 1

Views

Author

Clark Kimberling, Jun 05 2019

Keywords

Comments

Row n partitions A006128 into 2 parts, r(n,0) + r(n,1) = p(n) = A006128(n). What is the limiting behavior of r(n,0)/p(n)?

Examples

			First 15 rows:
    0    1
    1    2
    1    5
    4    8
    5   15
   11   24
   15   39
   28   58
   38   90
   62  130
   85  190
  131  268
  177  379
  258  522
  346  722
		

Crossrefs

Programs

  • Mathematica
    f[n_] := Mod[Flatten[IntegerPartitions[n]], 2];
    Table[Count[f[n], k], {n, 1, 40}, {k, 0, 1}]  (* A325771 array *)
    Flatten[%] (* A325771 sequence *)

Formula

(row n) = (A066898(n), A066897(n)).