cp's OEIS Frontend

A082741 Numbers that have digits consisting only of line segments or both line segments and curves (base 10 digits are 1, 2, 4, 5, 7).

%I A082741 #10 Apr 17 2022 14:34:16
%S A082741 1,2,4,5,7,11,12,14,15,17,21,22,24,25,27,41,42,44,45,47,51,52,54,55,
%T A082741 57,71,72,74,75,77,111,112,114,115,117,121,122,124,125,127,141,142,
%U A082741 144,145,147,151,152,154,155,157,171,172,174,175,177,211,212,214,215,217,221
%N A082741 Numbers that have digits consisting only of line segments or both line segments and curves (base 10 digits are 1, 2, 4, 5, 7).
%C A082741 This sequence allows the digits 2 and 5, formed from combinations of line segments and curves; the subsequence A028373 does not.
%H A082741 Alois P. Heinz, <a href="/A082741/b082741.txt">Table of n, a(n) for n = 1..1000</a>
%H A082741 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>.
%p A082741 a:= proc(n) local d, i, m, r; m:=n; r:=0;
%p A082741       for i from 0 while m>0 do
%p A082741         d:= irem(m, 5, 'm');
%p A082741         if d=0 then d:=5; m:=m-1 fi;
%p A082741         r:= r+10^i*[1, 2, 4, 5, 7][d]
%p A082741       od: r
%p A082741     end:
%p A082741 seq(a(n), n=1..100);  # _Alois P. Heinz_, May 25 2014
%t A082741 Table[FromDigits/@Tuples[{1,2,4,5,7},n],{n,3}]//Flatten (* _Harvey P. Dale_, Apr 17 2022 *)
%Y A082741 Cf. A028373 (line-segment digits 1, 4, 7 only), A028374 (digits with curves or both curves and line segments), A072960 (curved digits 0, 3, 6, 8, 9 only).
%K A082741 base,nonn,easy
%O A082741 1,2
%A A082741 _Rick L. Shepherd_, May 21 2003