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.

A323092 Number of double-free integer partitions of n.

This page as a plain text file.
%I A323092 #8 Feb 16 2025 08:33:57
%S A323092 1,1,2,2,4,5,7,10,14,17,24,30,40,50,66,81,104,128,161,197,246,300,369,
%T A323092 446,546,656,796,952,1148,1366,1637,1940,2311,2730,3234,3806,4489,
%U A323092 5262,6181,7225,8454,9846,11484,13335,15499,17948,20796,24017,27751,31970,36837
%N A323092 Number of double-free integer partitions of n.
%C A323092 An integer partition is double-free if no part is twice any other part.
%H A323092 Alois P. Heinz, <a href="/A323092/b323092.txt">Table of n, a(n) for n = 0..400</a>
%H A323092 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Double-FreeSet.html">Double-Free Set</a>
%e A323092 The a(1) = 1 through a(8) = 14 double-free integer partitions:
%e A323092   (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
%e A323092        (11)  (111)  (22)    (32)     (33)      (43)       (44)
%e A323092                     (31)    (41)     (51)      (52)       (53)
%e A323092                     (1111)  (311)    (222)     (61)       (62)
%e A323092                             (11111)  (411)     (322)      (71)
%e A323092                                      (3111)    (331)      (332)
%e A323092                                      (111111)  (511)      (431)
%e A323092                                                (4111)     (611)
%e A323092                                                (31111)    (2222)
%e A323092                                                (1111111)  (3311)
%e A323092                                                           (5111)
%e A323092                                                           (41111)
%e A323092                                                           (311111)
%e A323092                                                           (11111111)
%t A323092 Table[Length[Select[IntegerPartitions[n],Intersection[#,2*#]=={}&]],{n,30}]
%Y A323092 Cf. A018819, A051424, A101417, A120641, A276431, A305148, A323093, A323094.
%K A323092 nonn
%O A323092 0,3
%A A323092 _Gus Wiseman_, Jan 04 2019