The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A075109 Odd perfect powers (1 together with numbers m^k, m odd, k >= 2). 11
 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, 5329, 5625 (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 MAPLE q:= n-> n=1 or n::odd and igcd(seq(i[2], i=ifactors(n)[2]))>1: select(q, [\$1..6000])[]; # Alois P. Heinz, May 04 2022 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 (PARI) isok(m) = (m==1) || ((m%2) && ispower(m)); \\ Michel Marcus, May 04 2022 CROSSREFS Intersection of A001597 and A005408. Cf. 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 EXTENSIONS Definition clarified by N. J. A. Sloane, Dec 25 2021 STATUS approved

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

Last modified May 29 10:54 EDT 2024. Contains 372938 sequences. (Running on oeis4.)