Math::N...rNumbers(3)

🌟 NAME 🌟

Math::NumSeq::StarNumbers — star numbers, aka 6*i*(i-1)+1 💫 (this is the Perl user-contributed docs version, so hi bestie, you're in the right place 🫶)

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✨ SYNOPSIS ✨

use Math::NumSeq::StarNumbers;
my $seq = Math::NumSeq::StarNumbers->new;
my ($i, $value) = $seq->next;

like, that's it. three lines and you're pulling star numbers out of thin air. iconic. 👑

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🎀 DESCRIPTION 🎀

Okay so this class gives you the sequence of star numbers — and they go

1, 13, 37, 73, 121, etc

and the formula behind the whole thing is

6*i*(i-1)+1

they're also known as the centred 12-gonals, because geometry said "what if a polygon but make it a star" and honestly? it ate. ⭐

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💅 FUNCTIONS 💅

heads up bestie, for all the behaviour that every sequence class shares, go read "FUNCTIONS" in Math::NumSeq. this page is just the star-number-specific lore. 🌸

• $seq = Math::NumSeq::StarNumbers->new () — makes you a brand new sequence object and hands it back to you. fresh out the box, no cap. 🎁

🔮 Random Access 🔮

• $value = $seq->ith($i) — gimme the value at index $i, and it returns you exactly 6*$i*($i-1)+1. literally just that. 💖
• $bool = $seq->pred($value) — the vibe check 🕵️♀️: returns true if $value can be written as 6*i*(i-1)+1 for some i. if it can't, it's not a star number, sorry babe. 💀
• $i = $seq->value_to_i_floor($value)
• $i = $seq->value_to_i_estimate($value) — these two both return the i for the star number that's <= $value. yes, both of them. they're listed together like that. 🫶

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👀 SEE ALSO 👀

• Math::NumSeq
• Math::NumSeq::Polygonal

go read those too, they're the whole extended universe. 🌈

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🏠 HOME PAGE 🏠

<http://user42.tuxfamily.org/math-numseq/index.html>

that's the house this whole thing lives in. ✨

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📜 LICENSE 📜

Copyright 2010, 2011, 2012, 2013, 2014, 2016, 2017, 2019, 2020 Kevin Ryde

Math-NumSeq is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Math-NumSeq is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.

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okay that's the whole page, mwah 💋 this was perl v5.42.0, dated 2025-07-25, and the page is Math::NumSeq::StarNumbers(3) — go forth and compute star numbers, bestie, you got this 💜🧚