cp's OEIS Frontend

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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A365270 Practical numbers that have middle divisors.

Original entry on oeis.org

1, 2, 4, 6, 8, 12, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 48, 54, 56, 60, 64, 66, 72, 80, 84, 88, 90, 96, 100, 104, 108, 112, 120, 126, 128, 132, 140, 144, 150, 156, 160, 162, 168, 176, 180, 192, 196, 198, 200, 204, 208, 210, 216, 220, 224, 228, 234, 240, 252, 256
Offset: 1

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Author

Omar E. Pol, Aug 30 2023

Keywords

Comments

Very similar to A174973 from which differs at a(195) = 1014 here and 1020 there.
It appears that these are also the practical numbers k whose symmetric representation of sigma(k) has an odd number of parts.

Examples

			a(195) = 1014 is a practical number (A005153) and it has two middle divisors so 1014 is in the sequence.

Crossrefs

Intersection of A005153 and A071562.
Cf. A067742, A174973, A236104, A237270, A237271, A237591, A237593, A317412.
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