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A276254 With respect to the dictionary ordering of words over the alphabet {a,b}, i.e., e,a,b,aa,ab,ba,bb,aaa,..., the sequence is the characteristic function of the language of words that have no consecutive b's. 1
1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0

REFERENCES

R. G. Underwood, Fundamentals of Hopf Algebras, UTX, Springer, 2015, page 61.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..16383

Robert G. Underwood,A Class of Automatic Sequences , arXiv preprint arXiv:1712.10259, 2017

FORMULA

a(n) = 0 iff A007931(n) contains two (or more) consecutive 2's. - Alois P. Heinz, Aug 26 2016

MAPLE

a:= proc(n) local m, r, d; m, r:= n, 1;

      while m>0 do d:= irem(m, 2, 'm');

        if d=0 then if r=0 then return 0 fi;

          m:= m-1 fi; r:=d;

      od; 1

    end:

seq(a(n), n=0..200);  # Alois P. Heinz, Aug 25 2016

MATHEMATICA

a[n_] := Module[{m, r, d}, {m, r} = {n, 1}; While[m > 0, {m, d} = QuotientRemainder[m, 2]; If[d == 0, If[r == 0, Return[0]]; m = m-1]; r = d]; 1];

Table[a[n], {n, 0, 200}] (* Jean-Fran├žois Alcover, Mar 24 2018, after Alois P. Heinz *)

CROSSREFS

Cf. A007931.

Sequence in context: A327866 A190230 A141679 * A303300 A249865 A152904

Adjacent sequences:  A276251 A276252 A276253 * A276255 A276256 A276257

KEYWORD

nonn

AUTHOR

Robert G. Underwood, Aug 25 2016

EXTENSIONS

More terms from Alois P. Heinz, Aug 25 2016

STATUS

approved

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Last modified March 31 14:24 EDT 2020. Contains 333151 sequences. (Running on oeis4.)