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%I #11 Aug 03 2020 03:42:59
%S 1,3,7,17,37,83,181,399,863,1887,4057,8797,18851,40649,86911,186705,
%T 398413,853407,1818099,3885377,8266359,17632961,37473467,79814011,
%U 169457991,360469139,764700473,1624915019,3444615545,7312733017,15492242679,32862908109,69581860921,147497088201
%N Number of n-step self-avoiding walks on the half-Manhattan square lattice.
%C In the half-Manhattan lattice, E-W streets run alternately E and W, but N-S streets are two way.
%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a336/A336724.java">Java program</a> (github)
%Y Cf. A336705 (coordination sequence), A336742 (self-avoiding cycles), A117633 (Manhattan lattice), A001411 (square lattice), A322419 (L-lattice).
%K nonn,walk
%O 0,2
%A _Sean A. Irvine_, Aug 01 2020