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

1,2

Comments

Every term is a multiple of 12.

Links

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

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 *)

Prog

(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

Crossrefs

Cf. A027748, A124240, A141766.

Sequence in context: A033024 A044837 A033009 * A141766 A364710 A367338

Adjacent sequences: A140467 A140468 A140469 * A140471 A140472 A140473

Keyword

nonn

Author

Leroy Quet, Jun 28 2008

Extensions

More terms from Stefan Steinerberger, Jul 01 2008

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

Status

approved