%I #23 Jan 13 2014 09:35:55
%S 1,1,3,9,28,89,287,935,3072,10157,33767,112736,377836,1270203,4282311,
%T 14470629,49005732,166261653,565055147,1923186472,6554868916,
%U 22367933148,76417819396,261335128098,894597454360,3064970675173
%N Number of symmetric foldings of 2n+1 stamps.
%H J. E. Koehler, <a href="http://dx.doi.org/10.1016/S0021-9800(68)80048-1">Folding a strip of stamps</a>, J. Combin. Theory, 5 (1968), 135-152.
%H Stéphane Legendre, <a href="/A007822/a007822.pdf">Illustration of initial terms</a>
%H S. Legendre, <a href="http://arxiv.org/abs/1302.2025">Foldings and Meanders</a>, arXiv preprint arXiv:1302.2025, 2013.
%H S. Legendre, <a href="http://ajc.maths.uq.edu.au/58/ajc_v58_p275.pdf">Foldings and Meanders</a>, Aust. J. Comb. 58(2), 275-291, 2014.
%H W. F. Lunnon, <a href="http://dx.doi.org/10.1090/S0025-5718-1968-0221957-8 ">A map-folding problem</a>, Math. Comp. 22 (1968), 193-199.
%H <a href="/index/Fo#fold">Index entries for sequences obtained by enumerating foldings</a>
%Y Cf. A001010.
%K nonn
%O 1,3
%A _Stéphane Legendre_
%E More terms from _Stéphane Legendre_ (2013) added by _N. J. A. Sloane_, Mar 30 2013