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%I #11 Oct 11 2022 14:10:58
%S 1,3,7,15,27,47,71,107,151,207,271,355,447,563,691,835,995,1187,1391,
%T 1631,1887,2167,2467,2811,3171,3571,3995,4455,4939,5479,6035,6651,
%U 7299,7987,8707,9475,10267,11131,12031,12979,13959,15019,16103,17271,18479,19735
%N Number of length-n ternary sequences where the sum of each block differs by at most 1 from every other block of the same length.
%F a(n) = 2*A005598(n) - 1. - _Rémy Sigrist_, Oct 11 2022
%e For n = 2 the only strings omitted are 02 and 20.
%Y Cf. A005598, which is the analogous sequence where "ternary" is replaced by "binary".
%Y Cf. A274005, which is the analogous sequence where "ternary" is replaced by "binary" and "1" is replaced by "2".
%K nonn
%O 0,2
%A _Jeffrey Shallit_, Jun 06 2016
%E More terms from _Rémy Sigrist_, Oct 11 2022