A093021 - OEIS

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A093021

Indices of terms in A093019 with value 1.

1

9, 14, 28, 33, 47, 52, 66, 71, 85, 90, 108, 113, 127, 132, 146, 151, 165, 170, 189, 194, 207, 212, 226, 231, 245, 250, 269, 274, 288, 293, 306, 311, 325, 330, 349, 354, 368, 373, 387, 392, 405, 410, 429, 434, 448, 453, 467, 472, 486, 491, 504, 518, 523, 537

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Integers which require a following 1 to have a valid Luhn mod 10 check digit.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

John Kilgo, Using the Luhn Algorithm, DotNetJohn.com.

Webopedia, Luhn formula

Wikipedia, Luhn algorithm

Index entries for sequences related to decimal expansion of n

FORMULA

A093019(a(n)) = 1. - Reinhard Zumkeller, Nov 08 2014

EXAMPLE

14 is in the sequence because A093019(14)=1; 141 has a valid Luhn mod 10 check digit.

PROG

(Haskell)

a093021 n = a093021_list !! (n-1)

a093021_list = filter ((== 1) . a093019) [0..]

-- Reinhard Zumkeller, Nov 08 2014

CROSSREFS

Cf. A093017-A093029.

Sequence in context: A161547 A104812 A329751 * A360406 A272781 A229543

Adjacent sequences: A093018 A093019 A093020 * A093022 A093023 A093024

KEYWORD

easy,nonn,base

AUTHOR

Ray Chandler, Apr 03 2004

EXTENSIONS

Offset changed by Reinhard Zumkeller, Nov 08 2014

STATUS

approved