9976

From ProofWiki
Jump to navigation Jump to search

Previous  ... Next

Number

$9976$ (nine thousand, nine hundred and seventy-six) is:

$2^3 \times 29 \times 43$


The $58$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $7701$, $8008$, $8321$, $8640$, $8965$, $9296$, $9633$:
$9976 = \ds \sum_{k \mathop = 1}^{58} \paren {6 k - 5} = 58 \paren {3 \times 58 - 2}$


Also see