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A032829
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Numbers whose set of base-5 digits is {3,4}.
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2
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3, 4, 18, 19, 23, 24, 93, 94, 98, 99, 118, 119, 123, 124, 468, 469, 473, 474, 493, 494, 498, 499, 593, 594, 598, 599, 618, 619, 623, 624, 2343, 2344, 2348, 2349, 2368, 2369, 2373, 2374, 2468, 2469, 2473, 2474, 2493, 2494, 2498
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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(1)=3, a(2)=4; a(n) = 5*a(floor(n/2))+3 for n odd, otherwise a(n) = 5*a(floor((n-1)/2))+4. - Bruno Berselli, May 30 2012
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MATHEMATICA
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Flatten[Table[FromDigits[#, 5]&/@Tuples[{3, 4}, n], {n, 5}]] (* Vincenzo Librandi, May 29 2012 *)
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PROG
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(Magma) [n: n in [1..2800] | Set(IntegerToSequence(n, 5)) subset {3, 4}]; // Vincenzo Librandi, May 29 2012
(Maxima) a[1]:3$ a[2]:4$ a[n]:= if oddp(n) then 5*a[floor(n/2)]+3 else 5*a[floor((n-1)/2)]+4$ makelist(a[n], n, 1, 45); /* Bruno Berselli, May 30 2012 */
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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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STATUS
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approved
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