

A255568


Numbers in whose binary representation there are six 1bits more than there are nonleading 0bits.


2



63, 191, 223, 239, 247, 251, 253, 254, 639, 703, 735, 751, 759, 763, 765, 766, 831, 863, 879, 887, 891, 893, 894, 927, 943, 951, 955, 957, 958, 975, 983, 987, 989, 990, 999, 1003, 1005, 1006, 1011, 1013, 1014, 1017, 1018, 1020, 2303, 2431, 2495, 2527, 2543, 2551, 2555
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OFFSET

1,1


COMMENTS

Numbers for which A037861(n) = 6.
Numbers in whose binary representation (A007088) the number of 1bits = 6 + number of (nonleading) 0 bits.


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16303


EXAMPLE

63 ("111111" in binary) is included because there are 0 zerobits and six 1bits.
191 ("10111111" in binary) is included because there is 1 zerobit and seven 1bits, thus there are six 1bits more than the number of 0bits.


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A255568 (MATCHINGPOS 1 1 (lambda (n) (= 6 (A037861 n)))))
(Perl) use ntheory ":all"; my $bits = 0; for (1..1000) { my $o = hammingweight($_); $bits++ if ($_ & ($_1))==0; say if $o == 6+$bits$o; } # Dana Jacobsen, Dec 16 2015
(PARI) is(n)=2*hammingweight(n)==6+#binary(n) \\ Charles R Greathouse IV, Dec 16 2015
(PARI) for(b=3, 6, for(n=2^(2*b1), 4^b1, if(hammingweight(n)==3+b, print1(n", ")))) \\ Charles R Greathouse IV, Dec 16 2015
(PARI) listBBitMembers(b)=if(b%2, return([])); my(u=List()); forvec(v=vector(3+b/2, i, [0, b1]), listput(u, sum(i=1, #v, 2^v[i])), 2); Vec(u) \\ Charles R Greathouse IV, Dec 16 2015


CROSSREFS

Cf. A007088, A037861.
The intersection of A030130 and A023689 is a finite subsequence of this sequence.
Sequence in context: A008895 A008874 A045112 * A143033 A156527 A199850
Adjacent sequences: A255565 A255566 A255567 * A255569 A255570 A255571


KEYWORD

nonn,base,easy


AUTHOR

Antti Karttunen, Mar 11 2015


STATUS

approved



