Happy Number Checker
Check whether repeated sums of squared digits reach one rather than entering a cycle.
Description
Determine whether repeated sums of squared decimal digits eventually reach one.
Happy Number Checker determine whether repeated sums of squared decimal digits eventually reach one.
Use this for recreational mathematics, sequence exploration, loop-detection examples, and validating candidate happy numbers.
When to use Happy Number Checker
Use this for recreational mathematics, sequence exploration, loop-detection examples, and validating candidate happy numbers.
How it works
The tool repeatedly replaces the value with the sum of its decimal digits squared. It returns false when a previously seen value proves the sequence has entered a cycle.1
Interpreting the result
Keep the input units, direction conventions, encoding, and ordering rules visible when reusing the result. Preserve the full returned value for downstream calculations and round only for presentation.
Assumptions and limitations
This definition uses base ten and positive integers. The adjective happy is a sequence name, not an assessment of sentiment or user data.
References
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The On-Line Encyclopedia of Integer Sequences — OEIS Foundation