login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A075109 Odd perfect powers. 8
1, 9, 25, 27, 49, 81, 121, 125, 169, 225, 243, 289, 343, 361, 441, 529, 625, 729, 841, 961, 1089, 1225, 1331, 1369, 1521, 1681, 1849, 2025, 2187, 2197, 2209, 2401, 2601, 2809, 3025, 3125, 3249, 3375, 3481, 3721, 3969, 4225, 4489, 4761, 4913, 5041 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Sum_{n>=1} 1/a(n) = 1 + Sum_{k>=2} mu(k)*(1-zeta(k)*(2^k-1)/2^k) = 1.2890375574... - Amiram Eldar, Dec 19 2020

MATHEMATICA

Take[Union[Flatten[Table[a^b, {a, 1, 99, 2}, {b, 2, 15}]]], 50] (* Alonso del Arte, Nov 22 2011 *)

PROG

(Haskell)

a075109 n = a075109_list !! (n-1)

a075109_list = filter odd a001597_list  -- Reinhard Zumkeller, Oct 04 2012

(MAGMA) [1] cat [n : n in [3..6000 by 2] | IsPower(n) ]; // Vincenzo Librandi, Mar 31 2014

CROSSREFS

Cf. A001597, A008683, A075090.

Sequence in context: A275196 A325373 A062739 * A319165 A319152 A244623

Adjacent sequences:  A075106 A075107 A075108 * A075110 A075111 A075112

KEYWORD

easy,nonn

AUTHOR

Zak Seidov, Oct 11 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 16 07:59 EDT 2021. Contains 343030 sequences. (Running on oeis4.)