A048719 - OEIS

A048719

Binary expansion matches ((0)*0011)*(0*).

0, 3, 6, 12, 24, 48, 51, 96, 99, 102, 192, 195, 198, 204, 384, 387, 390, 396, 408, 768, 771, 774, 780, 792, 816, 819, 1536, 1539, 1542, 1548, 1560, 1584, 1587, 1632, 1635, 1638, 3072, 3075, 3078, 3084, 3096

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OFFSET

0,2

COMMENTS

1-bits occur only in pairs, separated from other such pairs by at least two 0-bits.

All terms satisfy both A048727(n) = 3*n and A048725(n) = 5*n.

LINKS

Table of n, a(n) for n=0..40.

Index entries for sequences defined by congruent products between domains N and GF(2)[X]

FORMULA

a(n) = 3*A048718(n).

MATHEMATICA

filterQ[n_] := With[{bb = IntegerDigits[n, 2]}, !MatchQ[bb, {1}|{1, 0, ___}|{___, 0, 1}|{___, 0, 1, 0, ___}|{___, 1, 1, 1, ___}|{___, 1, 0, 1, ___}]];

Select[Range[0, 3096], filterQ] (* Jean-François Alcover, Dec 31 2020 *)

PROG

(PARI) is(n)=n%3==0 && !bitand(n/3, 14*n/3) \\ Charles R Greathouse IV, Oct 03 2016

CROSSREFS

Intersection of A048716 and A048717.

Sequence in context: A137711 A068032 A293341 * A115807 A366277 A322676

Adjacent sequences: A048716 A048717 A048718 * A048720 A048721 A048722

KEYWORD

nonn,base,easy

AUTHOR

Antti Karttunen, Mar 30 1999

STATUS

approved