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 A033054 Numbers n such that base 3 representation Sum{d(i)*3^i: i=0,1,...,m} has d(i)=1 for m-i odd. 1
 1, 2, 4, 7, 12, 13, 14, 21, 22, 23, 37, 40, 43, 64, 67, 70, 111, 112, 113, 120, 121, 122, 129, 130, 131, 192, 193, 194, 201, 202, 203, 210, 211, 212, 334, 337, 340, 361, 364, 367, 388, 391, 394, 577, 580, 583, 604, 607, 610, 631 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA From Robert Israel, Jun 06 2016: (Start) a(3n+3) = 9a(n)+4. If A110654(n) is in A132141 then a(3n+2) = 9a(n)+3 and a(3n+4) = 9a(n)+5 otherwise a(3n+2) = 9a(n)+1 and a(3n+4) = 9a(n)+7. G.f. satisfies g(x) = 9(x^2+x^3+x^4)g(x^3) + (x+2x^2+4x^3+6x^4-x^5)/(1-x^3) + ((2+2x)/(x+x^2+x^3)) Sum_{k>=1}(x^(2*3^k)-x^(4*3^k)). (End) MAPLE N:= 1000: # to get a(1) to a(N) K:= ceil((N-4)/3): Dmax:= ilog[3](ceil(K/2+1)): A:= Vector(3*K+4): A[1..4]:= <1, 2, 4, 7>: for d from 0 to Dmax do   for k from 2*3^d-1 to min(4*3^d-2, K) do      A[3*k+2]:= 9*A[k]+3;      A[3*k+3]:= 9*A[k]+4;      A[3*k+4]:= 9*A[k]+5   od:   for k from 4*3^d-1 to min(2*3^(d+1)-2, K) do      A[3*k+2]:= 9*A[k]+1;      A[3*k+3]:= 9*A[k]+4;      A[3*k+4]:= 9*A[k]+7   od: od: seq(A[i], i=1..N); # Robert Israel, Jun 06 2016 CROSSREFS Sequence in context: A267699 A193841 A052474 * A266186 A181020 A049631 Adjacent sequences:  A033051 A033052 A033053 * A033055 A033056 A033057 KEYWORD nonn,base AUTHOR EXTENSIONS Name corrected by Robert Israel, Jun 06 2016 STATUS approved

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Last modified January 19 04:07 EST 2019. Contains 319304 sequences. (Running on oeis4.)