Re: A special kind of partitions of an integer
- To: mathgroup at smc.vnet.net
- Subject: [mg48161] Re: A special kind of partitions of an integer
- From: "Rob Pratt" <Rob.Pratt at sas.com>
- Date: Fri, 14 May 2004 20:59:25 -0400 (EDT)
- References: <200405131305.JAA24791@smc.vnet.net> <c81hq6$4uc$1@smc.vnet.net>
- Reply-to: "Rob Pratt" <Rob.Pratt at sas.com>
- Sender: owner-wri-mathgroup at wolfram.com
"Cezar Augusto de Freitas Anselmo" <cafa at ime.unicamp.br> wrote in message news:c81hq6$4uc$1 at smc.vnet.net... > Dear friends, > > I'm looking in literature theory of certain partitions of a integer. > > Have you worked with partitions of a integer n in n terms where the > summation is not associative (or know someone or texts about it, or > other discussion list)? > > Example: > I have to count P(n): the number of partitions of n with n positive > integers (the only so integer is one) terms where the + operator is not > associative, but is commutative; but the recurrence isn't simple. See > below > > 2 = (1+1); > (thus P(2)=1) > 3 = ((1+1)+1); > (thus P(3)=1) > 4 = (((1+1)+1)+1), ((1+1)+(1+1)); > (thus P(4)=2) > = ((((1+1)+1)+1)+1), (((1+1)+(1+1))+1), (((1+1)+1)+(1+1)); > (thus P(5)=3) > > > P(6)=6 > P(7)=11 > > Thanks for all help, > > -- > ======================================== > Cézar Freitas (ICQ 109128967) > IMECC - UNICAMP / IME - USP > Campinas / São Paulo, SP - Brasil http://www.research.att.com/projects/OEIS?Anum=A001190 Rob Pratt