|
%I #15 Aug 17 2021 07:13:04
%S 4,18,23,37,42,56,61,75,80,99,103,117,122,136,141,155,160,179,184,198,
%T 202,216,221,235,240,259,264,278,283,297,301,315,320,339,344,358,363,
%U 377,382,396,400,419,424,438,443,457,462,476,481,495,508,513,527,532
%N Indices of terms in A093019 with value 2.
%C Integers which require a following 2 to have a valid Luhn mod 10 check digit.
%H Reinhard Zumkeller, <a href="/A093022/b093022.txt">Table of n, a(n) for n = 1..10000</a>
%H John Kilgo, <a href="https://web.archive.org/web/20040627030859/http://www.dotnetjohn.com/articles/articleid97.aspx">Using the Luhn Algorithm</a>, DotNetJohn.com.
%H Webopedia, <a href="http://www.webopedia.com/TERM/L/Luhn_formula.html">Luhn formula</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Luhn_algorithm">Luhn algorithm</a>
%H <a href="/index/De#decimal_expansion">Index entries for sequences related to decimal expansion of n</a>
%F A093019(a(n)) = 2. - _Reinhard Zumkeller_, Nov 08 2014
%e 18 is in the sequence because A093019(18)=2; 182 has a valid Luhn mod 10 check digit.
%o (Haskell)
%o a093022 n = a093022_list !! (n-1)
%o a093022_list = filter ((== 2) . a093019) [0..]
%o -- _Reinhard Zumkeller_, Nov 08 2014
%Y Cf. A093017-A093029.
%K easy,nonn,base
%O 1,1
%A _Ray Chandler_, Apr 03 2004
%E Offset changed by _Reinhard Zumkeller_, Nov 08 2014
|
