[Jprogramming] Sequence generation

[Linda Alvord]

How about?

 f=: 13 :'+/"1(>:/~i.y)*(y#x)+/i.y'
   
   4 f 7
4 9 15 22 30 39 49

Linda
   

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On Thursday, September 28, 2017 Raul Miller <rauldmiller at gmail.com> wrote:
Nothing is simpler than the i. approach, but ^: is not significantly more complex than $: approach: }:(}:,+/@(_2&{.),>:@{:)^:9]4 4 9 15 22 30 39 49 60 72 Thanks, -- Raul 

On Thu, Sep 28, 2017 at 3:37 PM, Xiao-Yong Jin <jinxiaoyong at gmail.com> wrote: > > >> On Sep 28, 2017, at 1:40 PM, Raul Miller <rauldmiller at gmail.com> wrote: >> >> That is what I would assume: >> >> 4,(4+5),(4+5+6),(4+5+6+7),(4+5+6+7+8) >> 4 9 15 22 30 >> >> I was trying to figure out a recursive approach which isn't vastly >> more tedious... > > 4( [, +( ([,+)`$:@.(10>]) ) >:@])5 > > On the other hand, ^: can be used, but I don't see any simpler. > >> >> Thanks, >> >> -- >> Raul >> >> >> On Thu, Sep 28, 2017 at 2:39 PM, Roger Hui <rogerhui.canada at gmail.com> wrote: >>> You don't mean >>> >>> +/\4+i.10 >>> 4 9 15 22 30 39 49 60 72 85 >>> >>> do you? >>> >>> >>> >>> On Thu, Sep 28, 2017 at 11:33 AM, Skip Cave <skip at caveconsulting.com> wrote: >>> >>>> What is a good way to generate this sequence in J? >>>> >>>> 4,(4+5),(4+5+6),(4+5+6+7),(4+5+6+7+8)+..... >>>> >>>> Show one way using i. and insert. >>>> >>>> Show another way using recursion. >>>> >>>> Skip >>>> >>>> Skip Cave >>>> Cave Consulting LLC >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm