A140470 Numbers n such that p+1 divides n for every prime p that divides n.

1, 12, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 168, 180, 192, 216, 240, 264, 288, 300, 324, 336, 360, 384, 396, 432, 480, 504, 528, 540, 552, 576, 600, 612, 648, 660, 672, 720, 768, 792, 840, 864, 900, 960, 972, 1008, 1056, 1080, 1104, 1140, 1152, 1176

Offset: 1

Author

Leroy Quet, Jun 28 2008

Keywords

• nonn

Comments

Every term is a multiple of 12.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A027748, A124240, A141766.

Programs

Haskell

a140470 n = a140470_list !! (n-1)
a140470_list = filter
   (\x -> all (== 0) $ map ((mod x) . (+ 1)) $ a027748_row x) [1..]
-- Reinhard Zumkeller, Aug 27 2013

Mathematica

a = {}; For[n = 2, n < 1500, n++, b = Select[Range[n], PrimeQ[ # ] && Mod[n, # ] == 0 &]; c = 1; For[d = 1, d < Length[b] + 1, d++, If[Mod[n, b[[d]] + 1] > 0, c = 0; Break]]; If[c == 1, AppendTo[a, n]]]; a (* Stefan Steinerberger, Jul 01 2008 *)
eppQ[n_]:=Union[Differences/@Select[Partition[Divisors[n],2,1], PrimeQ[ #[[1]]]&]]=={{1}}; Join[{1},Select[Range[1200],eppQ]] (* Harvey P. Dale, May 27 2016 *)

Extensions

More terms from Stefan Steinerberger, Jul 01 2008

a(1)=1 prepended by Max Alekseyev, Aug 27 2013