superprismatic Posted September 4, 2009 Report Share Posted September 4, 2009 A sequence of numbers is generated by starting with an initial value n0 and computing subsequent values using the rule ni+1=ni+[sqrt(ni)]. Here [sqrt(ni)] represents the greatest integer in sqrt(ni). If n0 has no predecessor we shall call it a seed. For example, 11 is a seed since it cannot be produced by any number using the rule above. What is the seed corresponding to 1,000,000 (i.e., the unique value which generates the sequence containing 1,000,000 and which has no predecessor)? Quote Link to comment Share on other sites More sharing options...
0 bushindo Posted September 4, 2009 Report Share Posted September 4, 2009 (edited) A sequence of numbers is generated by starting with an initial value n0 and computing subsequent values using the rule ni+1=ni+[sqrt(ni)]. Here [sqrt(ni)] represents the greatest integer in sqrt(ni). If n0 has no predecessor we shall call it a seed. For example, 11 is a seed since it cannot be produced by any number using the rule above. What is the seed corresponding to 1,000,000 (i.e., the unique value which generates the sequence containing 1,000,000 and which has no predecessor)? JIZD Edited September 4, 2009 by bushindo Quote Link to comment Share on other sites More sharing options...
0 Guest Posted September 4, 2009 Report Share Posted September 4, 2009 I'm sorry, I can't resist & I respect the board rules about vulgarity & sexual references & so forth, but if this guy wants to sqrt his seed, that's his business. Meanwhile, it's a bit late & I'm going to sleep. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted September 4, 2009 Report Share Posted September 4, 2009 By brute force and some logic, I got 4031 as the seed for 1,000,000 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted September 4, 2009 Report Share Posted September 4, 2009 By brute force and some logic, I got 4031 as the seed for 1,000,000 I agree with DeeGee. With 4031 as the seed, n1877 gives 1,000,000. Quote Link to comment Share on other sites More sharing options...
Question
superprismatic
A sequence of numbers is generated by
starting with an initial value n0 and
computing subsequent values using the
rule ni+1=ni+[sqrt(ni)]. Here
[sqrt(ni)] represents the greatest
integer in sqrt(ni). If n0 has no
predecessor we shall call it a seed.
For example, 11 is a seed since it
cannot be produced by any number
using the rule above.
What is the seed corresponding to
1,000,000 (i.e., the unique value
which generates the sequence
containing 1,000,000 and which has
no predecessor)?
Link to comment
Share on other sites
4 answers to this question
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.