fibonacci() is one of the most recognizable functions in computer science.

Often used to demonstrate recursion, algorithm design, and computational complexity, the Fibonacci sequence is a classic entry point into deeper thinking.

From coding interviews to algorithm textbooks, it represents a small problem that exposes fundamental concepts: recursion, optimization, and mathematical structure.

For developers, it’s where abstract math becomes executable logic.

Simple function. Deeper concepts. Timeless pattern.

Because sometimes the most interesting problems start with a single function.

Product details

100% organic ring-spun cotton
5.3 oz./yd² (180 g/m²)
Single jersey construction
Medium fit
Set-in sleeves
1 × 1 ribbed collar
Double-needle stitching (sleeves & hem)
Self-fabric neck tape

Certified under GOTS, OCS, OEKO-TEX Standard 100, and PETA-Approved Vegan.

Blank product sourced from Bangladesh.

Note: Sizes correspond to a smaller fit in the US market. US customers may prefer ordering one size up.

Made on demand

This product is made especially for you as soon as you place an order, helping reduce overproduction.

Compliance

• Traceability:
- Weaving—Bangladesh
- Dyeing—Bangladesh
- Manufacturing—Bangladesh
• Contains 0% recycled polyester
• Contains 0% dangerous substances

Age restrictions: For adults
EU Warranty: 2 years
Meets EU REACH requirements

In compliance with the General Product Safety Regulation (GPSR), Developers Threads and SINDEN VENTURES LIMITED ensure product safety and EU standards.
Contact: gpsr@sindenventures.com
Address: Markou Evgenikou 11, Limassol, Cyprus

Size guide