login
Indices of terms in A093019 with value 8.
2

%I #15 Aug 17 2021 06:25:55

%S 1,15,20,39,44,58,63,77,82,96,100,119,124,138,143,157,162,176,181,195,

%T 204,218,223,237,242,256,261,275,280,299,303,317,322,336,341,355,360,

%U 379,384,398,402,416,421,435,440,459,464,478,483,497,505,510,529,534

%N Indices of terms in A093019 with value 8.

%C Integers which require a following 8 to have a valid Luhn mod 10 check digit.

%H Reinhard Zumkeller, <a href="/A093028/b093028.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)) = 8. - _Reinhard Zumkeller_, Nov 08 2014

%e 15 is in the sequence because A093019(15)=8; 158 has a valid Luhn mod 10 check digit.

%o (Haskell)

%o a093028 n = a093028_list !! (n-1)

%o a093028_list = filter ((== 8) . a093019) [0..]

%o -- _Reinhard Zumkeller_, Nov 08 2014

%Y Cf. A093017-A093029.

%K easy,nonn,base

%O 1,2

%A _Ray Chandler_, Apr 03 2004

%E Offset changed by _Reinhard Zumkeller_, Nov 08 2014