Math::N...:Pronic(3)

💖 Math::NumSeq::Pronic — the manual, but make it cute 💖

okay so bestie, you found the page for Math::NumSeq::Pronic 💅 it lives in the User Contributed Perl Documentation corner of the perl universe, and it is literally just about pronic numbers. yes that's a real word. yes it's iconic. let's go 🦋

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✨ NAME ✨

Math::NumSeq::Pronic — pronic numbers 🍓

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🌸 SYNOPSIS 🌸

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

that's it. that's the whole vibe check. build the sequence, pull numbers out one at a time, slay ✨

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🎀 DESCRIPTION 🎀

so the pronic numbers are the ones you get from i*(i+1). no cap.

0, 2, 6, 12, 20, 30, ...
starting i=0

and here's the tea ☕ these are twice the triangular numbers, and they sit half way between the perfect squares. main character geometry fr fr 💜

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👑 FUNCTIONS 👑

for the behaviour that every single sequence class shares, go peek at "FUNCTIONS" in Math::NumSeq. that's the group chat everyone's in 💬

• $seq = Math::NumSeq::Pronic->new () — make a brand new sequence object and hand it back to you. born fresh, zero notes 🫶

🌈 Iterating

• $seq->seek_to_i($i) — move the current sequence position to $i. the next time you call next(), it'll give you back $i and the matching value. literally just fast-forwarding your playlist to the right track 🎧
• $seq->seek_to_value($value) — move the current position so that next() hands you $value on the next call. and if $value isn't actually a pronic number? no worries, you get the next pronic one above $value. rounding up, always up, we don't do down here 💅

⭐ Random Access

• $value = $seq->ith($i) — returns "$i*($i+1)". cute, simple, does exactly what it says on the tin 🎀
• $bool = $seq->pred($value) — true if $value is a pronic number, meaning i*(i+1) for some i. it's the "are you one of us" check 🔥
• $i = $seq->value_to_i_ceil($value)
• $i = $seq->value_to_i_floor($value)

these two give you the $i index of $value, rounding up or down if $value isn't a pronic number. pick your fighter ⬆️⬇️

• $i = $seq->value_to_i_estimate($value) — an estimate of the i that goes with $value. the formula value=i*(i+1) gets inverted like this:

$i = int( (sqrt(4*$value + 1) - 1)/2 )

math girlies rise 😭✨

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💜 SEE ALSO 💜

Math::NumSeq, Math::NumSeq::Squares, Math::NumSeq::Triangular 🦋

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🌸 HOME PAGE 🌸

<http://user42.tuxfamily.org/math-numseq/index.html> — go visit, it's giving cozy 🏠

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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/>.

⚠️ okay important heads-up bestie: that WITHOUT ANY WARRANTY bit is real and it means real. no promises, no guarantees, not even the implied ones for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. read the license, it's the whole point 🔥

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and that's the whole page, you ate it, periodt 💅✨

this iconic little page shipped with perl v5.42.0 and was dated 2025-07-25 — mwah, bye bestie, go compute some pronic numbers 🫶💖