Ulam sequence
E85412
The Ulam sequence is an integer sequence starting with 1 and 2 in which each subsequent term is the smallest integer that can be written uniquely as the sum of two distinct earlier terms.
Statements (59)
| Predicate | Object |
|---|---|
| instanceOf |
integer sequence
→
mathematical sequence → |
| definedByRecurrence |
Each subsequent term is the smallest integer that can be written uniquely as the sum of two distinct earlier terms
→
|
| field |
number theory
→
|
| firstFewTerms |
1
→
102 → 106 → 11 → 114 → 128 → 13 → 131 → 138 → 139 → 148 → 155 → 156 → 16 → 166 → 177 → 18 → 180 → 189 → 2 → 26 → 28 → 3 → 36 → 38 → 4 → 47 → 48 → 53 → 57 → 6 → 62 → 69 → 71 → 78 → 8 → 81 → 85 → 97 → 99 → |
| hasFirstTerm |
1
→
|
| hasOEISID |
A002858
→
|
| hasOpenProblems |
true
→
|
| hasSecondTerm |
2
→
|
| hasSummandConstraint |
summands must be distinct earlier terms
→
|
| hasUniquenessConstraint |
sum representation must be unique
→
|
| isDeterministic |
true
→
|
| isInfinite |
true
→
|
| isNonPeriodic |
true
→
|
| isStrictlyIncreasing |
true
→
|
| namedAfter |
Stanisław Ulam
→
|
| requiresDistinctSummands |
true
→
|
| requiresUniqueRepresentationAsSum |
true
→
|
| startTermsFixed |
1 and 2
→
|
| usesOperation |
addition
→
|
Referenced by (1)
| Subject (surface form when different) | Predicate |
|---|---|
|
Stanislaw Ulam
→
|
notableWork |