

A236429


Number of representations of 0 as a sum of numbers d*k with d in {1,1} and k in {1,2,...,n}, where the sum of the numbers k is 2n.


1



1, 3, 6, 14, 25, 52, 86, 160, 260, 443, 688, 1146, 1721, 2716, 4040, 6176, 8975, 13482, 19218, 28167, 39799, 57081, 79503, 112987, 155368
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OFFSET

1,2


COMMENTS

a(n) = number of partitions of 2n that contain a partition of n.


LINKS

Table of n, a(n) for n=1..25.


EXAMPLE

a(3) counts these 6 representations of 0: 33, 321, 3111, 2+121, 2+1111, 1+1+1111.


MATHEMATICA

p[n_] := p[n] = IntegerPartitions[n]; Map[({p1 = p[#], p2 = p[2 #]} &[#]; Length[Cases[p2, Apply[Alternatives, Map[Flatten[{___, #, ___}] &, p1]]]]) &, Range[12]]
Map[({p1 = p[# + 1], p2 = p[2 # + 1]} &[#]; Length[Cases[p2, Apply[Alternatives, Map[Flatten[{___, #, ___}] &, p1]]]]) &, Range[12]]
(* Peter J. C. Moses, Jan 04 2014 *)


CROSSREFS

Cf. A236430, A235130.
Sequence in context: A166212 A291988 A285460 * A316245 A002219 A006906
Adjacent sequences: A236426 A236427 A236428 * A236430 A236431 A236432


KEYWORD

nonn,more


AUTHOR

Clark Kimberling, Jan 25 2014


STATUS

approved



