ntheory: fixes a doctest error by robustifying the doctest
ntheory: fixes a doctest error by robustifying the doctest

Signed-off-by: Ondrej Certik <b816faa87b7d35274d2e545c5be11ed4376f3ccf@certik.cz>

Designist/sympy,jamesblunt/sympy,moble/sympy,farhaanbukhsh/sympy,ahhda/sympy,amitjamadagni/sympy,sahmed95/sympy,pbrady/sympy,vipulroxx/sympy,jerli/sympy,pbrady/sympy,Vishluck/sympy,shipci/sympy,shikil/sympy,drufat/sympy,postvakje/sympy,wanglongqi/sympy,jbbskinny/sympy,sampadsaha5/sympy,atsao72/sympy,ahhda/sympy,Curious72/sympy,tovrstra/sympy,beni55/sympy,meghana1995/sympy,skidzo/sympy,asm666/sympy,sahmed95/sympy,kaushik94/sympy,Titan-C/sympy,shipci/sympy,iamutkarshtiwari/sympy,kumarkrishna/sympy,KevinGoodsell/sympy,liangjiaxing/sympy,mcdaniel67/sympy,meghana1995/sympy,chaffra/sympy,maniteja123/sympy,iamutkarshtiwari/sympy,MechCoder/sympy,ryanGT/sympy,meghana1995/sympy,kumarkrishna/sympy,dqnykamp/sympy,grevutiu-gabriel/sympy,Mitchkoens/sympy,chaffra/sympy,sahilshekhawat/sympy,pandeyadarsh/sympy,ahhda/sympy,lidavidm/sympy,lidavidm/sympy,wyom/sympy,aktech/sympy,cccfran/sympy,minrk/sympy,toolforger/sympy,wanglongqi/sympy,AunShiLord/sympy,atreyv/sympy,Vishluck/sympy,dqnykamp/sympy,cswiercz/sympy,souravsingh/sympy,mcdaniel67/sympy,mafiya69/sympy,madan96/sympy,abhiii5459/sympy,AkademieOlympia/sympy,oliverlee/sympy,srjoglekar246/sympy,sahilshekhawat/sympy,hrashk/sympy,emon10005/sympy,jaimahajan1997/sympy,flacjacket/sympy,pbrady/sympy,pandeyadarsh/sympy,sampadsaha5/sympy,skidzo/sympy,kumarkrishna/sympy,liangjiaxing/sympy,atreyv/sympy,kaichogami/sympy,MridulS/sympy,beni55/sympy,Arafatk/sympy,cccfran/sympy,saurabhjn76/sympy,jbbskinny/sympy,hrashk/sympy,jamesblunt/sympy,Sumith1896/sympy,jbaayen/sympy,debugger22/sympy,Gadal/sympy,abloomston/sympy,skirpichev/omg,moble/sympy,madan96/sympy,ChristinaZografou/sympy,Sumith1896/sympy,AkademieOlympia/sympy,drufat/sympy,amitjamadagni/sympy,Davidjohnwilson/sympy,MridulS/sympy,MridulS/sympy,ga7g08/sympy,hargup/sympy,postvakje/sympy,farhaanbukhsh/sympy,mcdaniel67/sympy,Shaswat27/sympy,chaffra/sympy,sunny94/temp,lindsayad/sympy,wanglongqi/sympy,mafiya69/sympy,garvitr/sympy,saurabhjn76/sympy,pandeyadarsh/sympy,cswiercz/sympy,atsao72/sympy,MechCoder/sympy,VaibhavAgarwalVA/sympy,skidzo/sympy,Vishluck/sympy,AunShiLord/sympy,hargup/sympy,Designist/sympy,emon10005/sympy,Designist/sympy,diofant/diofant,kaushik94/sympy,fperez/sympy,kaichogami/sympy,sahilshekhawat/sympy,Mitchkoens/sympy,jamesblunt/sympy,Arafatk/sympy,sampadsaha5/sympy,rahuldan/sympy,abloomston/sympy,rahuldan/sympy,shikil/sympy,jerli/sympy,lindsayad/sympy,bukzor/sympy,sahmed95/sympy,saurabhjn76/sympy,Gadal/sympy,yukoba/sympy,Titan-C/sympy,debugger22/sympy,lindsayad/sympy,liangjiaxing/sympy,hrashk/sympy,MechCoder/sympy,Gadal/sympy,kmacinnis/sympy,garvitr/sympy,Titan-C/sympy,farhaanbukhsh/sympy,jerli/sympy,Arafatk/sympy,Davidjohnwilson/sympy,Curious72/sympy,shikil/sympy,maniteja123/sympy,Curious72/sympy,kevalds51/sympy,asm666/sympy,maniteja123/sympy,yukoba/sympy,oliverlee/sympy,kevalds51/sympy,asm666/sympy,grevutiu-gabriel/sympy,kevalds51/sympy,beni55/sympy,yashsharan/sympy,vipulroxx/sympy,yashsharan/sympy,Shaswat27/sympy,ga7g08/sympy,mafiya69/sympy,ChristinaZografou/sympy,abloomston/sympy,aktech/sympy,rahuldan/sympy,kmacinnis/sympy,AkademieOlympia/sympy,hargup/sympy,hazelnusse/sympy-old,wyom/sympy,kaichogami/sympy,grevutiu-gabriel/sympy,lidavidm/sympy,vipulroxx/sympy,hazelnusse/sympy-old,jaimahajan1997/sympy,debugger22/sympy,emon10005/sympy,souravsingh/sympy,VaibhavAgarwalVA/sympy,wyom/sympy,sunny94/temp,mattpap/sympy-polys,yashsharan/sympy,pernici/sympy,postvakje/sympy,Shaswat27/sympy,Sumith1896/sympy,oliverlee/sympy,atsao72/sympy,shipci/sympy,ChristinaZografou/sympy,ga7g08/sympy,dqnykamp/sympy,bukzor/sympy,cccfran/sympy,garvitr/sympy,jbbskinny/sympy,moble/sympy,abhiii5459/sympy,cswiercz/sympy,jaimahajan1997/sympy,bukzor/sympy,VaibhavAgarwalVA/sympy,drufat/sympy,sunny94/temp,toolforger/sympy,souravsingh/sympy,kaushik94/sympy,kmacinnis/sympy,aktech/sympy,madan96/sympy,minrk/sympy,iamutkarshtiwari/sympy,yukoba/sympy,toolforger/sympy,AunShiLord/sympy,Mitchkoens/sympy,abhiii5459/sympy,Davidjohnwilson/sympy,atreyv/sympy