A265125 -id:A265125 - cp's OEIS frontend

A175943 Partial products of A027746.

1, 2, 6, 12, 24, 120, 240, 720, 5040, 10080, 20160, 40320, 120960, 362880, 725760, 3628800, 39916800, 79833600, 159667200, 479001600, 6227020800, 12454041600, 87178291200, 261534873600, 1307674368000, 2615348736000, 5230697472000

Offset: 1

Lior Manor, Oct 27 2010

nonn

a(n) <= A265125(n), a(n) < A265125(n) for n > 10. - Reinhard Zumkeller, Dec 02 2015

Charles R Greathouse IV, Table of n, a(n) for n = 1..1000

n! (A000142) is a subsequence.
Cf. A027746.
Cf. A265125.

a175943 n = a175943_list !! (n-1)
a175943_list = scanl1 (*) $ concat a027746_tabf
-- Reinhard Zumkeller, Dec 02 2015

print1(t=1); for(n=2, 10, f=factor(n); for(i=1, #f[,1], for(j=1,f[i,2], print1(", "t*=f[i,1])))) \\ Charles R Greathouse IV, Sep 12 2012

a(n) is approximately (n / (e log log n))^(n/log log n). - Charles R Greathouse IV, Sep 12 2012

A265111 A rearrangement of the terms of A027746 (seen as flat list) such that adjacent terms are distinct.

Original entry on oeis.org

1, 2, 3, 2, 5, 2, 3, 2, 7, 2, 3, 2, 5, 3, 2, 11, 2, 3, 2, 13, 2, 7, 2, 5, 3, 2, 17, 2, 3, 2, 19, 3, 2, 5, 2, 7, 3, 2, 11, 2, 23, 2, 3, 2, 5, 2, 13, 5, 2, 3, 2, 7, 3, 2, 29, 3, 2, 5, 3, 2, 31, 2, 11, 3, 2, 17, 2, 7, 5, 2, 3, 2, 37, 3, 2, 19, 2, 13, 3, 2, 5, 2

Offset: 1

Reinhard Zumkeller, Dec 01 2015

nonn

			.  k  | 1 2 3 4   5 6   7 8     9   10   11 12     13 14  15  16       17
.     | 1 2 3 2*2 5 2*3 7 2*2*2 3*3 2*5  11 2*2*3  13 2*7 3*5 2*2*2*2  17
. ----+-------------------------------------------------------------------
. a(n)| 1 2 3 2 5 2 3 2 7 2 3 2 5 3 2 11 2  3 2 13 2  7 2 5 3 2 17 2 3 2 ..

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

Cf. A027746, A265125 (partial products).

a265111 n = a265111_list !! (n-1)
a265111_list = 1 : f 1 [] 0 1 where
   f u [] w x = f 1 (reverse $ a027746_row' (u * x)) w (x + 1)
   f u (v:vs) w x | v == w    = f (u * v) vs w x
                  | otherwise = v : f u vs v x

cp's OEIS Frontend

A175943 Partial products of A027746.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

Haskell

PARI

Formula