Generate List of Numbers

This systematic number sequence creator produces ordered numerical lists following arithmetic progressions, customizable ranges, or pattern-based rules, outputting sequences useful for spreadsheet population, database ID generation, test data sets, or systematic sampling frameworks. The generator handles various sequencing requirements from simple increments through complex multi-step patterns.

Users define sequence parameters specifying start value (initial number), end value or length (determining sequence bounds), and step size (increment between consecutive values). Basic modes generate linear sequences (1, 2, 3...), arithmetic progressions (0, 5, 10, 15...), or countdown series (100, 90, 80...), while advanced options support geometric progressions (powers of two: 1, 2, 4, 8...), custom formulas calculating each term based on position, or random sequences within specified bounds combining order with variability. Format controls adjust decimal places for floating-point sequences, add thousands separators for readability in large values, or prepend/append prefixes and suffixes creating formatted identifiers (ID-001, ID-002...).

Output options produce comma-separated lists for inline use, line-separated columns for vertical data entry, or structured formats (JSON arrays, SQL INSERT statements) for database seeding. Preview displays sample values confirming pattern correctness before generating large sequences, statistics report total count and range span for verification, and length warnings prevent accidental extremely large generations that might freeze browsers. Practical applications include creating sequential invoice numbers for batch invoice systems, generating test user IDs for application development, populating spreadsheet rows with systematic values, creating lottery number combinations, or establishing sampling frames for statistical surveys requiring systematic selection. The tool handles large sequence generation efficiently through streaming or chunked processing, supports clipboard integration for rapid data transfer, and validates parameters preventing impossible configurations like negative step values in increasing sequences.