A169884 Numbers consisting of either all even digits or just 5's and 0's.

0, 2, 4, 5, 6, 8, 20, 22, 24, 26, 28, 40, 42, 44, 46, 48, 50, 55, 60, 62, 64, 66, 68, 80, 82, 84, 86, 88, 200, 202, 204, 206, 208, 220, 222, 224, 226, 228, 240, 242, 244, 246, 248, 260, 262, 264, 266, 268, 280, 282, 284, 286, 288, 400, 402, 404, 406

Offset: 1

Author

David Applegate, Marc LeBrun and N. J. A. Sloane, Jul 06 2010

Keywords

• nonn
• base
• easy
• changed

Comments

These are all the divisors of zero in carryless arithmetic mod 10. E.g. 5 * 44 = 0.

Links

• David Applegate, Marc LeBrun and N. J. A. Sloane, Carryless Arithmetic (I): The Mod 10 Version.
• Index entries for 10-automatic sequences.
• Index entries for sequences related to carryless arithmetic

Crossrefs

Cf. A004520, A059729, A168294, A168541, A169885, A169886, A169887.

Programs

Mathematica

With[{upto=410},Select[Union[Join[Select[Range[upto],And@@EvenQ[ IntegerDigits[#]]&], FromDigits/@Tuples[{5,0},Ceiling[Log[ 10,upto]]]]],#<=upto&]] (* Harvey P. Dale, Aug 05 2011 *)
elect[Range[0,500],AllTrue[IntegerDigits[#],EvenQ]||SubsetQ[{0,5},IntegerDigits[#]]&] (* Harvey P. Dale, Aug 22 2025 *)