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%I #7 Nov 29 2012 15:07:31
%S 47,147,247,347,447,470,547,647,747,847,947,1047,1147,1247,1347,1447,
%T 1470,1547,1647,1747,1847,1947,2047,2147,2247,2347,2447,2470,2547,
%U 2647,2747,2847,2947,3047,3147,3247,3347,3447,3470
%N Numbers n such that string 4,7 occurs in the base 10 representation of n but not of n-1.
%t Select[Range[4000],MemberQ[Partition[IntegerDigits[#],2,1],{4,7}] && !MemberQ[Partition[IntegerDigits[#-1],2,1],{4,7}]&] (* _Harvey P. Dale_, Nov 29 2012 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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