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3, 5, 11, 13, 35, 37, 43, 45, 131, 133, 139, 141, 163, 165, 171, 173, 515, 517, 523, 525, 547, 549, 555, 557, 643, 645, 651, 653, 675, 677, 683, 685, 2051, 2053, 2059, 2061, 2083, 2085, 2091, 2093, 2179, 2181, 2187, 2189, 2211, 2213, 2219, 2221, 2563, 2565, 2571
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OFFSET
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0,1
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COMMENTS
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Every odd number m>=9 is a unique sum of the form a(k)+2a(l); moreover this sequence is the unique one with such property. In connection with A103151, note that there is no subsequence T of primes such that every odd number m>=9 is expressible as a unique sum of the form m=p+2q, where p and q are in T. One can prove that if one replaces 9 by any integer x_o>9, the statement remains true (see the Shevelev link).
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LINKS
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MATHEMATICA
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(* b = A000695 *) b[n_] := If[n==0, 0, If[EvenQ[n], 4 b[n/2] , b[n-1]+1]];
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PROG
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(PARI) a000695(n) = fromdigits(binary(n), 4);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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