

A330220


Numbers whose representation in base 2^w contains only the digit 2^k for some w and k such that 0 <= k < w


1



0, 1, 2, 3, 4, 5, 7, 8, 9, 10, 15, 16, 17, 18, 21, 31, 32, 33, 34, 36, 42, 63, 64, 65, 66, 68, 73, 85, 127, 128, 129, 130, 132, 136, 146, 170, 255, 256, 257, 258, 260, 264, 273, 292, 341, 511, 512, 513, 514, 516, 520, 528, 546, 585, 682, 1023, 1024, 1025, 1026
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OFFSET

1,3


COMMENTS

For any k > 0, there are k nonzero terms with k binary digits.


LINKS



EXAMPLE

The representation of 546 in base 2^4 is "222", so 546 belongs to the sequence.


PROG

(PARI) is(n) = { for (w=1, max(1, #binary(n)), my (d=if (n, digits(n, 2^w), [0])); if (#Set(d)==1 && hammingweight(d[1])<=1, return (1))); return (0) }


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



