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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A307117 Numbers x that are equal to lpf(x)*gpf(x)*(lpf(x)+gpf(x))/2, where lpf(x) and gpf(x) are the least and the greatest prime factors of x: A020639 and A006530.

Original entry on oeis.org

8, 27, 105, 125, 231, 343, 627, 897, 935, 1331, 1581, 1729, 2197, 2465, 2967, 3525, 4123, 4301, 4715, 4913, 5487, 6859, 7035, 7685, 7881, 9717, 10707, 11339, 12167, 14993, 16377, 17353, 17655, 20213, 20915, 23779, 24389, 24765, 25327, 26331, 26765, 29341, 29607
Offset: 1

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Author

Alex Ratushnyak, Mar 25 2019

Keywords

Comments

This is A307108 with terms such that lpf(x)=gpf(x), that is, with cubes of primes.

Crossrefs

Cf. A000040, A020639, A006530, A307108.
Cf. A262723 is the subsequence with terms such that lpf(x)!=gpf(x), and (lpf(x)+gpf(x))/2 a prime.
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