A044399 - OEIS

A044399

Numbers n such that string 6,7 occurs in the base 10 representation of n but not of n-1.

%I #7 Sep 24 2013 09:03:08

%S 67,167,267,367,467,567,667,670,767,867,967,1067,1167,1267,1367,1467,

%T 1567,1667,1670,1767,1867,1967,2067,2167,2267,2367,2467,2567,2667,

%U 2670,2767,2867,2967,3067,3167,3267,3367,3467,3567

%N Numbers n such that string 6,7 occurs in the base 10 representation of n but not of n-1.

%t Select[Range[4000],MemberQ[Partition[IntegerDigits[#],2,1],{6,7}] && !MemberQ[Partition[IntegerDigits[#-1],2,1],{6,7}]&] (* _Harvey P. Dale_, Sep 24 2013 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_