|
Search: id:A071985
|
|
|
| A071985 |
|
a(n) is the smallest positive integer that cannot be obtained using at most n-1 of the integers {1, 2, ..., n} using each number at most once and the operators +, -, *, /. |
|
+0
1
|
| |
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
For all n>=2, A060315(n+1) > a(n) > A060315(n).
|
|
LINKS
|
G. Bannay, LE COMPTE EST BON
Index entries for similar sequences
|
|
EXAMPLE
|
a(3)=7 because using two of the numbers {1,2,3} with the four operations we can obtain 1=1, 2=2, 3=3, 3+1=4, 3+2=5, 3*2=6 but we cannot obtain 7 in the same way.
|
|
CROSSREFS
|
Cf. A060315.
Adjacent sequences: A071982 A071983 A071984 this_sequence A071986 A071987 A071988
Sequence in context: A106191 A062810 A113985 this_sequence A090977 A014144 A096358
|
|
KEYWORD
|
hard,more,nonn
|
|
AUTHOR
|
Koksal Karakus (karakusk(AT)hotmail.com), Jun 17 2002
|
|
|
Search completed in 0.002 seconds
|
