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A280609 Odd prime powers with prime exponents. 0
9, 25, 27, 49, 121, 125, 169, 243, 289, 343, 361, 529, 841, 961, 1331, 1369, 1681, 1849, 2187, 2197, 2209, 2809, 3125, 3481, 3721, 4489, 4913, 5041, 5329, 6241, 6859, 6889, 7921, 9409, 10201, 10609, 11449, 11881, 12167, 12769, 16129, 16807, 17161, 18769, 19321, 22201, 22801, 24389, 24649, 26569, 27889, 29791, 29929 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A053810 and A061345.

LINKS

Table of n, a(n) for n=1..53.

Eric Weisstein's World of Mathematics, Prime Power

FORMULA

a(n) = p^q, where p, q are primes and p > 2.

EXAMPLE

9 is in the sequence because 9 = 3^2;

25 is in the sequence because 25 = 5^2;

27 is in the sequence because 27 = 3^3, etc.

MATHEMATICA

Select[Range[30000], PrimePowerQ[#1] && PrimeQ[PrimeOmega[#1]] && Mod[#1, 2] == 1 & ]

CROSSREFS

Cf. A000961, A034785, A053810, A061345, A078422, A246547, A246551, A246655.

Sequence in context: A244623 A339127 A117580 * A340238 A020308 A108989

Adjacent sequences:  A280606 A280607 A280608 * A280610 A280611 A280612

KEYWORD

nonn,easy

AUTHOR

Ilya Gutkovskiy, Jan 06 2017

STATUS

approved

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Last modified June 16 21:55 EDT 2021. Contains 345080 sequences. (Running on oeis4.)