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A175755 Numbers with 49 divisors. 5
46656, 1000000, 7529536, 11390625, 85766121, 113379904, 308915776, 1291467969, 1544804416, 1838265625, 3010936384, 3518743761, 9474296896, 17596287801, 27680640625, 34296447249, 38068692544, 56800235584, 75418890625, 107918163081, 164206490176, 208422380089 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers of the forms p^48 and p^6*q^6, where p and q are distinct primes.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

OEIS Wiki, Index entries for number of divisors

FORMULA

A000005(a(n))=49.

EXAMPLE

a(1) = A114334(49); a(2) = A159765(49).

MATHEMATICA

Select[Range[100000000], DivisorSigma[0, #]==48&] (* Vladimir Joseph Stephan Orlovsky, May 06 2011 *)

PROG

(Haskell)

a175755 n = a175755_list !! (n-1)

a175755_list = m (map (^ 48) a000040_list) (map (^ 6) a006881_list) where

   m xs'@(x:xs) ys'@(y:ys) | x < y = x : m xs ys'

                           | otherwise = y : m xs' ys

-- Reinhard Zumkeller, Nov 29 2011

(PARI) is(n)=numdiv(n)==49 \\ Charles R Greathouse IV, Jun 19 2016

CROSSREFS

Cf. A139575, A175754, A201266, A137488, A135581.

Sequence in context: A057068 A223510 A251190 * A223562 A016866 A016914

Adjacent sequences:  A175752 A175753 A175754 * A175756 A175757 A175758

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Aug 27 2010

EXTENSIONS

Extended by T. D. Noe, May 08 2011

STATUS

approved

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Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)