Menu Close

what-is-the-value-of-coefficient-of-x-9-in-expansion-1-x-1-x-2-1-x-3-1-x-4-1-x-100-




Question Number 93450 by john santu last updated on 13/May/20
what is the value of coefficient  of x^9  in expansion (1+x)(1+x^2 )  (1+x^3 )(1+x^4 )×...×(1+x^(100) ) ?
whatisthevalueofcoefficientofx9inexpansion(1+x)(1+x2)(1+x3)(1+x4)××(1+x100)?
Answered by john santu last updated on 13/May/20
Answered by mr W last updated on 13/May/20
it is the number of partitions from 9  into distinct parts, which is q(9)=8.  similarly   the coef. of x^5 =q(5)=3.  the coef. of x^(12) =q(12)=15.  the coef. of x^(50) =q(50)=3658.
itisthenumberofpartitionsfrom9intodistinctparts,whichisq(9)=8.similarlythecoef.ofx5=q(5)=3.thecoef.ofx12=q(12)=15.thecoef.ofx50=q(50)=3658.
Commented by john santu last updated on 13/May/20
what formula to get it?
whatformulatogetit?
Commented by mr W last updated on 14/May/20
there is no closed formula for q(n).  see following:
thereisnoclosedformulaforq(n).seefollowing:
Commented by mr W last updated on 14/May/20

Leave a Reply

Your email address will not be published. Required fields are marked *