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A077476
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Numbers n such that the digital binary sum of n equals core(n), the squarefree part of n.
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1
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1, 4, 16, 18, 64, 72, 256, 288, 405, 486, 726, 847, 1024, 1125, 1152, 1183, 1620, 1734, 1944, 2166, 2646, 2904, 3174, 3388, 4096, 4500, 4608, 4732, 5766, 6480, 6534, 6727, 6936, 7776, 8664, 10584, 11616, 12250, 12696, 13552, 14406, 16384, 16807, 18000
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OFFSET
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1,2
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LINKS
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EXAMPLE
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486 = 2*3^5 hence the squarefree part of 486 is 2*3=6 and the binary representation of 486 is 111100110_2 with 6 1's, hence 486 is in the sequence.
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PROG
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(PARI) is(n)=my(h=hammingweight(n), t=n/h); denominator(t)==1 && issquare(t) && issquarefree(h) \\ Charles R Greathouse IV, Mar 29 2013
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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