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A192545 Numbers such that all numbers are composite when replacing exactly one digit with another, except the leading digit with zero. 3
200, 202, 204, 205, 206, 208, 320, 322, 324, 325, 326, 328, 510, 512, 514, 515, 516, 518, 530, 532, 534, 535, 536, 538, 620, 622, 624, 625, 626, 628, 840, 842, 844, 845, 846, 848, 890, 892, 894, 895, 896, 898, 1070, 1072, 1074, 1075, 1076, 1078, 1130, 1132 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A048853(a(n)) = 0;

Intersection of this sequence and A000040 is A158124. - Evgeny Kapun, Dec 13 2016

If the last digit of an element is 0, 2, 4, 5, 6 or 8, then replacing it with 0, 2, 4, 5, 6 or 8 also yields an element. - David A. Corneth and corrected by Evgeny Kapun, Dec 13 2016

LINKS

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

MATHEMATICA

Select[Range@ 1200, Function[w, Total@ Boole@ Flatten@ Map[Function[d, PrimeQ@ FromDigits@ ReplacePart[w, d -> #] & /@ If[d == 1, #, Prepend[#, 0]] &@ Range@ 9], Range@ Length@ w] == 0]@ IntegerDigits@ # &] (* Michael De Vlieger, Dec 13 2016 *)

PROG

(Haskell)

import Data.List (elemIndices)

a192545 n = a192545_list !! (n-1)

a192545_list = map (+ 1) $ elemIndices 0 $ map a048853 [1..]

CROSSREFS

Subsequences: A050249, A118118, A143641, A158124, A158125.

Sequence in context: A239525 A180104 A114984 * A118118 A124472 A247399

Adjacent sequences:  A192542 A192543 A192544 * A192546 A192547 A192548

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Jul 05 2011

STATUS

approved

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Last modified October 14 11:51 EDT 2019. Contains 327997 sequences. (Running on oeis4.)