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A052423 Highest common factor of nonzero digits of n. 4
1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 7, 1, 1, 1, 1, 1, 1, 7, 1, 1, 8, 1, 2, 1, 4, 1, 2, 1, 8, 1, 9, 1, 1, 3, 1, 1, 3, 1, 1, 9, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(A069715(n)) = 1. - Reinhard Zumkeller, Apr 14 2014

LINKS

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

EXAMPLE

a(46)=2 because highest common factor of 4 and 6 is 2.

PROG

(PARI) a(n) = {digs = digits(n, 10); hcf = digs[1]; for (i = 2, #digs, if (digs[i], hcf = gcd(hcf, digs[i])); ); return (hcf); } \\ Michel Marcus, Jul 27 2013

(Haskell)

a052423 n = f n n where

   f x 1 = 1

   f x y | x < 10    = gcd x y

         | otherwise = if d == 1 then 1 else f x' (gcd d y)

         where (x', d) = divMod x 10

-- Reinhard Zumkeller, Apr 14 2014

CROSSREFS

Cf. A007954.

Sequence in context: A075877 A133500 A256229 * A126616 A121042 A000030

Adjacent sequences:  A052420 A052421 A052422 * A052424 A052425 A052426

KEYWORD

base,easy,nonn

AUTHOR

Henry Bottomley, Mar 17 2000

STATUS

approved

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Last modified February 23 05:44 EST 2018. Contains 299473 sequences. (Running on oeis4.)