A235507 Harshad numbers which when divided by sum of their digits, give a quotient which is a Harshad number.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42, 45, 48, 50, 54, 60, 63, 70, 72, 80, 81, 84, 90, 100, 108, 120, 162, 180, 200, 210, 216, 240, 243, 270, 300, 324, 360, 378, 400, 405, 420, 432, 450, 480, 486, 500, 540, 600, 630, 648, 700, 720

Offset: 1

Author

Mihir Mathur, Jan 14 2014

Keywords

• nonn
• base

Comments

These numbers are also called MHN-2 or Multiple Harshad Numbers-2.

Examples

			486 is a MHN as it is divisible by the sum of its digits i.e. 18. The quotient obtained, 27, is also divisible by the sum of its digits, i.e. 9.
		

Links

• Ray Chandler, Table of n, a(n) for n = 1..10796 (all a(n) <= 10^6)
• Wikipedia, Harshad Number

Crossrefs

Cf. A005349, A235697.

Programs

Mathematica

mhnQ[n_]:=Module[{s=Total[IntegerDigits[n]]},Divisible[n,s]&&Divisible[ n/s,Total[IntegerDigits[n/s]]]]; Select[Range[800],mhnQ] (* Harvey P. Dale, Sep 02 2017 *)