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A034305 Nonprime numbers n such that n remains nonprime if any digit deleted (zeros not allowed in n). 12
14, 16, 18, 44, 46, 48, 49, 64, 66, 68, 69, 81, 84, 86, 88, 91, 94, 96, 98, 99, 122, 124, 125, 126, 128, 142, 144, 145, 146, 148, 152, 154, 155, 156, 158, 162, 164, 165, 166, 168, 182, 184, 185, 186, 188, 212, 214, 215, 216, 218, 221, 222, 224, 225, 226, 228 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe and Reinhard Zumkeller, Table of n, a(n) for n = 1..10000, first 1000 terms from T. D. Noe

PROG

(Haskell)

a034305 n = a034305_list !! (n-1)

a034305_list = filter f $ drop 9 a052382_list where

  f x = a010051' x == 0 &&

        (all (== 0) $ map (a010051' . read) $

         zipWith (++) (inits $ show x) (tail $ tails $ show x))

-- Reinhard Zumkeller, May 10 2015

(PARI) is(n)=my(d=digits(n)); if(#d<2 || vecmin(d)<1 || isprime(n), return(0)); for(i=0, #d-1, if(isprime(fromdigits(vecextract(d, 2^#d-1-2^i))), return(0))); 1 \\ Charles R Greathouse IV, Jun 25 2017

CROSSREFS

Subsequence of A052382.

Cf. A034302-A034304, A010051.

Sequence in context: A053425 A178071 A177982 * A091898 A061365 A102107

Adjacent sequences:  A034302 A034303 A034304 * A034306 A034307 A034308

KEYWORD

base,nonn,nice

AUTHOR

David W. Wilson

EXTENSIONS

Definition corrected by T. D. Noe, Apr 02 2008

STATUS

approved

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Last modified August 22 05:00 EDT 2019. Contains 326172 sequences. (Running on oeis4.)