# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a144794 Showing 1-1 of 1 %I A144794 #10 Aug 20 2017 23:30:52 %S A144794 4,8,9,12,16,17,19,24,25,28,32,33,35,36,39,48,49,51,56,57,60,64,65,67, %T A144794 68,71,72,73,76,79,96,97,99,100,103,112,113,115,120,121,124,128,129, %U A144794 131,132,135,136,137,140,143,144,145,147,152,153,156,159,192,193,195,196 %N A144794 A positive integer n is included if every 0 in binary n is next to at least one other 0. %C A144794 n is included if A144789(n) >= 2. %H A144794 Michael De Vlieger, Table of n, a(n) for n = 1..10000 %p A144794 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 %t A144794 Select[Range@ 200, And[Union@ # != {1}, AllTrue[Map[Length, Select[Split@ #, First@ # == 0 &]], # > 1 &]] &@ IntegerDigits[#, 2] &] (* _Michael De Vlieger_, Aug 20 2017 *) %Y A144794 Cf. A144789, A144795. %K A144794 base,nonn %O A144794 1,1 %A A144794 _Leroy Quet_, Sep 21 2008 %E A144794 Extended by _R. J. Mathar_, Sep 29 2008 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE