OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..300
FORMULA
If p <= n < q, where p and q are consecutive primes, then a(n) = (2p)!/n!, unless n=10.
MATHEMATICA
a75365[n_] := Module[{div, k, pr}, div=Times@@Prime/@Range[PrimePi[n]]; For[k=0; pr=1, True, k++; pr*=n+k, If[Mod[pr, div]==0, Return[k]]]]; a[n_] := Times@@Range[n+1, n+a75365[n]]
PROG
(Haskell)
a075366 n = a075366_list !! (n-1)
a075366_list = 1 : f 2 1 a000040_list where
f x pp ps'@(p:ps)
| p <= x = f x (p * pp) ps
| otherwise = g $ dropWhile (< pp) $ scanl1 (*) [x+1, x+2 ..]
where g (z:zs) | mod z pp == 0 = z : f (x + 1) pp ps'
| otherwise = g zs
-- Reinhard Zumkeller, May 18 2015
CROSSREFS
KEYWORD
nice,nonn
AUTHOR
Amarnath Murthy, Sep 20 2002
EXTENSIONS
Edited by Dean Hickerson, Oct 28 2002
STATUS
approved