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%I M2846 #50 Feb 10 2024 12:52:39
%S 1,1,3,10,33,147,620,2821,12942,60639,286190,1364621,6545430,31586358,
%T 153143956,745700845,3644379397,17869651166,87877879487,433301253231,
%U 2141584454057,10607707971062,52646117638427,261756764824964,1303625908234997,6502430891223011,32480041218465452,162454295068924189,813541940383789255,4078750395194965720
%N Number of one-sided hexagonal polyominoes with n cells.
%D J. Meeus, personal communication.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H John Mason, <a href="/A006535/b006535.txt">Table of n, a(n) for n = 1..36</a>
%H J. Meeus & N. J. A. Sloane, <a href="/A006532/a006532_1.pdf">Correspondence, 1974-1975</a>
%H Ed Pegg, Jr., <a href="http://demonstrations.wolfram.com/PolyformExplorer/">Illustrations of polyforms</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Polyhex.html">Polyhex</a>
%F a(n) = 2*A000228(n) - A030225(n).
%Y Cf. A000228, A030225, A001207.
%K nonn,hard,nice
%O 1,3
%A _N. J. A. Sloane_
%E a(7)-a(12) from _David W. Wilson_
%E a(13) from _Achim Flammenkamp_, Feb 15 1999
%E a(14)-a(20) from _Joseph Myers_, Sep 21 2002
%E a(21)-a(30) from _John Mason_, Jul 18 2023
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