I like that solution. Here is another approach
4 p.~(2&^@>: ,.~ _1r3 * 2&^@>: + _1&^)i. 10
7 15 29 59 117 235 469 939 1877 3755
I found this by composing the linear poly's and noting the constant
terms satisfy a two step recursion with eigenvalues 2 and _1.
lc=.({.@[+{:@[*{.@]),*&{:
lc/\.(7$_1 2,:1 2)
_43 128
_21 64
_11 32
_5 16
_3 8
_1 4
_1 2
On 11/27/2018 11:06 AM, Raul Miller wrote:
Sure, ... that's a bit bulkier than I prefer, but it works.
Here's another alternative:
evenodd=: , (_1 2,:_1 4)&p.@{:
evenodd evenodd 4
4 7 15 29 59
Thanks,
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