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%I #11 Oct 29 2015 23:04:46
%S 1,2,5,10,21,1365,2730
%N Numbers without consecutive repeated digits in base 2 and in base 3.
%C Intersection of A000975 and A031941. - _Michel Marcus_, Oct 14 2015
%C It seems likely that there are no further terms.
%e 10 is 1010 in base 2 and 101 in base 3; no two of the same digit are next to one another and so 10 is a term.
%e Similarly 21 is 10101 in base 2 and 210 in base 3 so it is also a term.
%o (PARI) isokd(d) = {dd = vector(#d-1, k, abs(d[k+1]-d[k])); if (#dd, vecmin(dd), 1);}
%o isok(n) = isokd(binary(n)) && isokd(digits(n, 3)); \\ _Michel Marcus_, Oct 14 2015
%Y Cf. A000975 (base 2), A031941 (base 3).
%K nonn,base
%O 1,2
%A _Robin Powell_, Oct 13 2015