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A032834
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Numbers with digits 3 and 4 only.
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16
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3, 4, 33, 34, 43, 44, 333, 334, 343, 344, 433, 434, 443, 444, 3333, 3334, 3343, 3344, 3433, 3434, 3443, 3444, 4333, 4334, 4343, 4344, 4433, 4434, 4443, 4444, 33333, 33334, 33343, 33344, 33433, 33434, 33443, 33444, 34333, 34334
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listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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FORMULA
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a(2*n+1) = 10*a(n)+3.
a(2*n+2) = 10*a(n)+4.
G.f. g(x) satisfies g(x) = 10*(x+x^2)*g(x^2) + x*(3+4*x)/(1-x^2). (End)
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MAPLE
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S[1]:= [3, 4]:
for d from 2 to 5 do S[d]:= map(t -> (10*t+3, 10*t+4), S[d-1]) od:
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MATHEMATICA
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Flatten[Table[FromDigits[#, 10]&/@Tuples[{3, 4}, n], {n, 5}]] (* Vincenzo Librandi, May 30 2012 *)
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PROG
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(Magma) [n: n in [1..35000] | Set(IntegerToSequence(n, 10)) subset {3, 4}]; // Vincenzo Librandi, May 30 2012
(PARI) A032834(n)=vector(#n=binary(n+1)[2..-1], i, 10^(#n-i))*n~+10^#n\3 \\ M. F. Hasler, Mar 27 2015
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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