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%I #6 Aug 07 2020 00:57:02
%S 1,3,21,47,227,499,2321,5087,23429,51263,235881,515691,2372511,
%T 5185609,23856215,52139887,239863701,524238555,2411688233,5270900439,
%U 24248031407,52995614649
%N Number of symmetric n X 4 crossword puzzle grids.
%Y Cf. A001333, A034184-A034187.
%K nonn
%O 1,2
%A _Erich Friedman_
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