login
A144794
A positive integer n is included if every 0 in binary n is next to at least one other 0.
3
4, 8, 9, 12, 16, 17, 19, 24, 25, 28, 32, 33, 35, 36, 39, 48, 49, 51, 56, 57, 60, 64, 65, 67, 68, 71, 72, 73, 76, 79, 96, 97, 99, 100, 103, 112, 113, 115, 120, 121, 124, 128, 129, 131, 132, 135, 136, 137, 140, 143, 144, 145, 147, 152, 153, 156, 159, 192, 193, 195, 196
OFFSET
1,1
COMMENTS
n is included if A144789(n) >= 2.
LINKS
MAPLE
A007814 := proc(n) local nshf, a ; a := 0 ; nshf := n ; while nshf mod 2 = 0 do nshf := nshf/2 ; a := a+1 ; od: a ; end: A144789 := proc(n) option remember ; local lp2, lp2sh, bind ; bind := convert(n, base, 2) ; if add(i, i=bind) = nops(bind) then RETURN(0) ; fi; lp2 := A007814(n) ; if lp2 = 0 then A144789(floor(n/2)) ; else lp2sh := A144789(n/2^lp2) ; if lp2sh = 0 then lp2 ; else min(lp2, lp2sh) ; fi; fi; end: isA144794 := proc(n) RETURN(A144789(n) >= 2) ; end: for n from 3 to 400 do if isA144794(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Sep 29 2008
MATHEMATICA
Select[Range@ 200, And[Union@ # != {1}, AllTrue[Map[Length, Select[Split@ #, First@ # == 0 &]], # > 1 &]] &@ IntegerDigits[#, 2] &] (* Michael De Vlieger, Aug 20 2017 *)
CROSSREFS
Sequence in context: A359829 A221865 A004753 * A047462 A020671 A171598
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Sep 21 2008
EXTENSIONS
Extended by R. J. Mathar, Sep 29 2008
STATUS
approved