OFFSET
1,4
EXAMPLE
20 in binary is 10100. The runs of 0's are as follows: 1(0)1(00). The shortest of these runs contains exactly one 0's So a(20) = 1.
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: for n from 1 to 140 do printf("%d, ", A144789(n)) ; od: # R. J. Mathar, Sep 29 2008
MATHEMATICA
Table[Min[Length/@Select[Split[IntegerDigits[n, 2]], MemberQ[#, 0]&]], {n, 120}]/.\[Infinity]->0 (* Harvey P. Dale, Jul 24 2016 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Sep 21 2008
EXTENSIONS
Extended by R. J. Mathar, Sep 29 2008
STATUS
approved