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A244623 Odd prime powers that are not primes. 1
1, 9, 25, 27, 49, 81, 121, 125, 169, 243, 289, 343, 361, 529, 625, 729, 841, 961, 1331, 1369, 1681, 1849, 2187, 2197, 2209, 2401, 2809, 3125, 3481, 3721, 4489, 4913, 5041, 5329, 6241, 6561, 6859, 6889, 7921, 9409, 10201, 10609, 11449, 11881, 12167, 12769, 14641, 15625, 16129, 16807, 17161, 18769, 19321, 19683 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Intersection of A061345 and A014076.

A014076 set minus A061346.

LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A079290(n) at least in the range n=3..94, and perhaps beyond. - R. J. Mathar, Aug 20 2014

MATHEMATICA

Join[{1}, Select[Range[1, 20001, 2], PrimePowerQ[#]&&(!PrimeQ[#])&]] (* Harvey P. Dale, Dec 11 2018 *)

PROG

(Sage)

def isA244623(n) :

   return(n % 2 == 1 and is_prime_power(n) == 1 and is_prime(n) == 0)

[n for n in (1..20000) if isA244623(n)]

CROSSREFS

Cf. A061345 (odd prime powers), A061346 (odd neither prime nor prime power), A062739 (odd powerful), A075109 (perfect powers).

Sequence in context: A075109 A319165 A319152 * A117580 A280609 A020308

Adjacent sequences:  A244620 A244621 A244622 * A244624 A244625 A244626

KEYWORD

nonn

AUTHOR

Jani Melik, Jul 02 2014

STATUS

approved

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Last modified September 16 08:36 EDT 2019. Contains 327091 sequences. (Running on oeis4.)