A049073 LCM of all divisors of d of n such that d+1 is a prime power.

1, 2, 3, 4, 1, 6, 7, 8, 3, 10, 1, 12, 1, 14, 15, 16, 1, 18, 1, 20, 21, 22, 1, 24, 1, 26, 3, 28, 1, 30, 31, 16, 3, 2, 7, 36, 1, 2, 3, 40, 1, 42, 1, 44, 15, 46, 1, 48, 7, 10, 3, 52, 1, 18, 1, 56, 3, 58, 1, 60, 1, 62, 63, 16, 1, 66, 1, 4, 3, 70, 1, 72, 1, 2, 15, 4, 7, 78, 1, 80, 3, 82, 1, 84, 1

Offset

1,2

Comments

a(A185208(n)) = 1. - Reinhard Zumkeller, Nov 01 2012

Links

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

Index entries for sequences related to lcm's

Mathematica

a[n_] := LCM @@ Select[Divisors[n], PrimeNu[# + 1] == 1 &]; Table[a[n], {n, 1, 85}] (* Jean-François Alcover, Aug 17 2013 *)

Prog

(Haskell)
a049073 = foldl lcm 1 . filter ((== 1) . a010055 . (+ 1)) . a027750_row
-- Reinhard Zumkeller, Nov 01 2012

Crossrefs

Cf. A141197, A027750, A010055.

Sequence in context: A105587 A345998 A319676 * A076388 A354988 A264977

Adjacent sequences: A049070 A049071 A049072 * A049074 A049075 A049076

Keyword

nonn,easy,nice

Author

David E. Daykin

Extensions

More terms from Erich Friedman, Jun 03 2001

Status

approved