A162823 Positive numbers k such that 42*k/(42-k) are integers.

6, 14, 21, 24, 28, 30, 33, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 51, 54, 56, 60, 63, 70, 78, 84, 91, 105, 126, 140, 168, 189, 238, 294, 336, 483, 630, 924, 1806

Offset

1,1

Comments

The number k=42 is explicitly included, treating the result of division through zero as an integer.

Row 42 of A191973.

Links

Table of n, a(n) for n=1..41.

Maple

for m from 1 to 1806 do if(m=42 or m*42 mod (m-42) = 0)then printf("%d, ", m): fi: od: # Nathaniel Johnston, Jun 22 2011

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
Join[{42}, Select[Range[2000], IntegerQ[(42#)/(42-#)]&]]//Quiet//Sort (* Harvey P. Dale, Mar 14 2020 *)

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819, A162820, A162821, A162822, A191973.

Sequence in context: A371396 A118129 A046712 * A020171 A122784 A244175

Adjacent sequences: A162820 A162821 A162822 * A162824 A162825 A162826

Keyword

nonn,fini,full,easy

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Extensions

Keywords fini,full added by R. J. Mathar, Jul 31 2009

Status

approved