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0, 0, 0, 1, -1, 0, 4, 7, -7, -6, 0, 3, 13, 18, 28, 35, -35, -34, -24, -21, -5, 0, 14, 21, 43, 52, 70, 81, 105, 118, 140, 155, -155, -154, -136, -133, -105, -100, -78, -71, -35, -26, 0, 11, 47, 60, 90, 105, 151, 168, 202, 221, 265, 286, 324, 347, 399, 424, 466, 493, 545, 574, 620, 651, -651, -650, -616, -613, -561
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OFFSET
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0,7
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COMMENTS
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The positions of the zeros seem to be given by A000975.
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LINKS
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FORMULA
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MATHEMATICA
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A048702 := Join[{0}, Reap[For[k = 1, k < 1500, k += 2, bb = IntegerDigits[k, 2]; If[bb == Reverse[bb], If[EvenQ[Length[bb]], Sow[k/3]]]]][[2, 1]]]; Table[n*(n + 1)/2 - A048702[[n + 1]], {n, 0, 50}] (* G. C. Greubel, Sep 26 2017 *)
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PROG
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(PARI) a01(n) = my(f); f = length(binary(n)) - 1; 2^(f+1)*n + sum(i=0, f, bittest(n, i) * 2^(f-i)); \\ A048701
a(n) = n*(n+1)/2 - a01(n)/3; \\ A006095
(Python)
s = bin(n)[2:]
return n * (n + 1) // 2 - int(s + s[::-1], 2) // 3
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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