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%I #12 Mar 11 2019 10:56:36
%S 1,2,4,6,10,18,32,55,98,173,307,543,962,1705,3021,5354,9489,16818,
%T 29810,52836,93649,165987,294205,521464,924270,1638225,2903678,
%U 5146634,9122172,16168628,28658146,50795242,90032221,159577957,282844564,501328936,888582404
%N a(n) = ceiling(Pi^(n/2)).
%t Ceiling[Pi^(Range[0,40]/2)] (* _Harvey P. Dale_, May 28 2015 *)
%Y Cf. A000796, A102475.
%K nonn
%O 0,2
%A Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Feb 24 2005
%E a(0)=1 prepended by _Alois P. Heinz_, Feb 27 2019