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

Offset: 2

Author

Michel Marcus, Dec 09 2012

Keywords

• base
• nonn
• more

Comments

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

Examples

			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
		

Links

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

Crossrefs

Cf. A133219.

Extensions

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