A162818 Strictly positive numbers n such that (42*n)/(42+n) is an integer.

7, 21, 42, 56, 84, 105, 154, 210, 252, 399, 546, 840, 1722

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Keywords

• nonn
• fini
• full

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817

Cf. A127730 - Franklin T. Adams-Watters, Aug 07 2009

Programs

Mathematica

f[a_,b_]:=(a*b)/(a+b); a=42;lst={};Do[If[f[a,n]==IntegerPart[f[a,n]],AppendTo[lst,n]],{n,9!}];lst
Select[Range[2000], Divisible[42 #, 42 + #] &] (* Harvey P. Dale, May 09 2012 *)

Extensions

Keywords fini and full added by Franklin T. Adams-Watters, Aug 07 2009