A220289 - OEIS

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A220289

Smallest composite integer in base n which remains composite after altering any one or two digits.

1010100, 2200100, 12321230, 324322330, 43040303150, 5411665056000, 33254100107730, 210324811482600, 977731833235239280

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OFFSET

2,1

COMMENTS

Unlike A133219, changing the most significant digit to 0 is disallowed.

LINKS

Table of n, a(n) for n=2..10.

Witold Jarnicki and Maciej Zenczykowski, On a property of the number 977731833235239280, arXiv:0709.3361 [math.NT], 2007.

EXAMPLE

Expressed in base 10, the terms from n=2 to 9 are: 84, 1953, 28268, 1401590, 273241578, 77478704205, 1878528135128, 48398467146642. - edited by Michel Marcus, Sep 27 2014

CROSSREFS

Cf. A133219.

Sequence in context: A234035 A330519 A066354 * A133219 A306515 A306517

Adjacent sequences: A220286 A220287 A220288 * A220290 A220291 A220292

KEYWORD

base,nonn,more

AUTHOR

Michel Marcus, Dec 09 2012

EXTENSIONS

Typo for a(10) corrected by Michel Marcus, Sep 27 2014

STATUS

approved