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Arithmetic Sequence Reference Index Shift

Shift an explicit arithmetic-sequence reference term by a signed exact integer index displacement.

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Description

Rebase an arithmetic-sequence term using a supplied common difference.

Sequence calculations depend on the reference index, common difference or ratio, and whether a domain uses exact integers or real-valued arithmetic. Alternation depends on index parity; modular arithmetic chooses a representative in a fixed residue interval. A supplied local rule is not discovered from data and need not establish a complete recurrence or prediction model.

Rebase an arithmetic-sequence term using a supplied common difference.

When to use this tool

Use Arithmetic Sequence Reference Index Shift when you already have referenceTerm, commonDifference, referenceIndex, targetIndex and need to rebase an arithmetic-sequence term using a supplied common difference.

How to use the tool and how it works

  1. Enter referenceTerm, commonDifference, referenceIndex, targetIndex. Use the units and conventions below.
  2. Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
  3. Read targetTerm. Use the output convention below.

Require signed safe whole indices; form target-reference using BigInt, convert that difference to a number, and return referenceTerm+difference*commonDifference.1

Input fieldMeaning and unitsAccepted input
referenceTermReference TermRequired. Finite number.
commonDifferenceCommon DifferenceRequired. Finite number.
referenceIndexReference IndexRequired. Safe integer.
targetIndexTarget IndexRequired. Safe integer.
Output fieldInterpretationReturned shape
targetTermTarget TermRequired. Finite number.
json
{
  "input": {
    "referenceTerm": 10,
    "commonDifference": 3,
    "referenceIndex": 5,
    "targetIndex": 8
  },
  "output": {
    "targetTerm": 19
  }
}

Limitations and assumptions

  • This assumes an arithmetic model; a large index difference or product can lose precision and no pattern is discovered.
  • Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
  • Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use the complete sequence definition and initial conditions for recurrence analysis. Choose exact integer or rational arithmetic when large indices or exact terms matter; local reference shifts and residue operations do not discover a generating rule.

References

  1. Calculation and input contract: sequence/arithmetic-sequence-reference-index-shift — tool.io

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