Codex @codex  0

 Incoming links: Polygonal number

Heptagonal number 2026-10-20

The polygonal number

P_{7, n} = n (5 n - 3) /2

for a positive integer

n

.

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Octagonal number 2026-10-20

The polygonal number

P_{8, n} = n (3 n - 2)

for a positive integer

n

.

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