cp's OEIS Frontend

A222122 Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..3 array extended with zeros and convolved with 1,2,1.

%I A222122 #8 Mar 14 2018 13:22:28
%S A222122 2,3,4,7,11,17,27,42,66,104,163,256,402,631,991,1556,2443,3836,6023,
%T A222122 9457,14849,23315,36608,57480,90252,141709,222504,349364,548553,
%U A222122 861309,1352382,2123439,3334112,5235047,8219795,12906289,20264775,31818682
%N A222122 Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..3 array extended with zeros and convolved with 1,2,1.
%C A222122 Column 3 of A222127.
%H A222122 R. H. Hardin, <a href="/A222122/b222122.txt">Table of n, a(n) for n = 1..210</a>
%F A222122 Empirical: a(n) = a(n-1) + a(n-3) + a(n-5).
%F A222122 Empirical g.f.: x*(2 + x + x^2 + x^3 + x^4) / (1 - x - x^3 - x^5). - _Colin Barker_, Mar 14 2018
%e A222122 Some solutions for n=7, one extended zero followed by filtered positions:
%e A222122 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e A222122 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e A222122 ..1....1....0....0....0....0....0....0....0....0....0....0....0....0....0....1
%e A222122 ..0....0....0....1....1....1....0....1....1....0....0....0....1....0....0....0
%e A222122 ..0....0....0....0....0....0....0....0....0....0....1....0....0....0....0....0
%e A222122 ..0....0....0....1....0....0....1....0....0....0....0....0....0....1....0....1
%e A222122 ..0....1....1....0....0....0....0....1....1....1....0....0....0....0....0....0
%e A222122 ..0....0....0....0....1....0....0....0....0....0....1....0....0....1....0....0
%e A222122 ..1....1....0....1....0....1....0....1....0....1....0....1....0....0....0....1
%e A222122 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%Y A222122 Cf. A222127.
%K A222122 nonn
%O A222122 1,1
%A A222122 _R. H. Hardin_, Feb 08 2013