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%I #20 Dec 07 2015 02:04:26
%S 1,1,2,4,10,23,63,155,448,1152,3451,9156,28155,76491,240015,664363,
%T 2118804,5954414,19246816,54772539,179063855,515006165,1700131496,
%U 4934242781,16427135058,48050970367,161163698861,474656662565,1602509174036,4748224219223,16125057102402
%N Meandric numbers for a river crossing up to 9 parallel roads at n points.
%C Number of ways that a river (or directed line) that starts in the South and flows East can cross up to 9 parallel East-West roads n times.
%C Sequence derived from list of solutions described in A206432.
%H Andrew Howroyd, <a href="/A209621/b209621.txt">Table of n, a(n) for n = 0..36</a>
%Y Cf. A005316 (sequence for one road; extensive references and links).
%Y Cf. A076876 (sequence for two parallel roads).
%Y Cf. A204352, A208062, A208126, A208452, A208453, A209383, A209621, A209622, A209626, A209656, A209657, A209660, A209707, A210344, A210478, A210567, A210592 (sequences for 3 to 19 parallel roads).
%Y Cf. A206432 (sequence for unlimited number of parallel roads).
%Y Cf. A076875, A076906, A076907.
%K nonn
%O 0,3
%A _Robert Price_, May 07 2012
%E a(21)-a(36) from _Andrew Howroyd_, Dec 06 2015