trepan rtepan terpan etrpan retpan ertpan trpean rtpean tprean ptrean rptean prtean tepran etpran tperan pteran eptran petran reptan erptan rpetan pretan eprtan pertan treapn rteapn terapn etrapn retapn ertapn traepn rtaepn tarepn atrepn ratepn artepn tearpn etarpn taerpn aterpn eatrpn aetrpn reatpn eratpn raetpn aretpn eartpn aertpn trpaen rtpaen tpraen ptraen rptaen prtaen trapen rtapen tarpen atrpen ratpen artpen tparen ptaren tapren atpren patren aptren rpaten praten rapten arpten parten aprten teparn etparn tpearn ptearn eptarn petarn teaprn etaprn taeprn ateprn eatprn aetprn tpaern ptaern tapern atpern patern aptern epatrn peatrn eaptrn aeptrn paetrn apetrn repatn erpatn rpeatn preatn epratn peratn reaptn eraptn raeptn areptn earptn aerptn rpaetn praetn rapetn arpetn paretn apretn epartn peartn eaprtn aeprtn paertn apertn trepna rtepna terpna etrpna retpna ertpna trpena rtpena tprena ptrena rptena prtena teprna etprna tperna pterna eptrna petrna reptna erptna rpetna pretna eprtna pertna trenpa rtenpa ternpa etrnpa retnpa ertnpa trnepa rtnepa tnrepa ntrepa rntepa nrtepa tenrpa etnrpa tnerpa nterpa entrpa netrpa rentpa erntpa rnetpa nretpa enrtpa nertpa trpnea rtpnea tprnea ptrnea rptnea prtnea trnpea rtnpea tnrpea ntrpea rntpea nrtpea tpnrea ptnrea tnprea ntprea pntrea nptrea rpntea prntea rnptea nrptea pnrtea nprtea tepnra etpnra tpenra ptenra eptnra petnra tenpra etnpra tnepra ntepra entpra netpra tpnera ptnera tnpera ntpera pntera nptera epntra pentra enptra neptra pnetra npetra repnta erpnta rpenta prenta eprnta pernta renpta ernpta rnepta nrepta enrpta nerpta rpneta prneta rnpeta nrpeta pnreta npreta epnrta penrta enprta neprta pnerta nperta treanp rteanp teranp etranp retanp ertanp traenp rtaenp tarenp atrenp ratenp artenp tearnp etarnp taernp aternp eatrnp aetrnp reatnp eratnp raetnp aretnp eartnp aertnp trenap rtenap ternap etrnap retnap ertnap trneap rtneap tnreap ntreap rnteap nrteap tenrap etnrap tnerap nterap entrap netrap rentap erntap rnetap nretap enrtap nertap tranep rtanep tarnep atrnep ratnep artnep trnaep rtnaep tnraep ntraep rntaep nrtaep tanrep atnrep tnarep ntarep antrep natrep rantep arntep rnatep nratep anrtep nartep teanrp etanrp taenrp atenrp eatnrp aetnrp tenarp etnarp tnearp ntearp entarp netarp tanerp atnerp tnaerp ntaerp anterp naterp eantrp aentrp enatrp neatrp anetrp naetrp reantp erantp raentp arentp earntp aerntp renatp ernatp rneatp nreatp enratp neratp ranetp arnetp rnaetp nraetp anretp naretp eanrtp aenrtp enartp neartp anertp naertp trpane rtpane tprane ptrane rptane prtane trapne rtapne tarpne atrpne ratpne artpne tparne ptarne taprne atprne patrne aptrne rpatne pratne raptne arptne partne aprtne trpnae rtpnae tprnae ptrnae rptnae prtnae trnpae rtnpae tnrpae ntrpae rntpae nrtpae tpnrae ptnrae tnprae ntprae pntrae nptrae rpntae prntae rnptae nrptae pnrtae nprtae tranpe rtanpe tarnpe atrnpe ratnpe artnpe trnape rtnape tnrape ntrape rntape nrtape tanrpe atnrpe tnarpe ntarpe antrpe natrpe rantpe arntpe rnatpe nratpe anrtpe nartpe tpanre ptanre tapnre atpnre patnre aptnre tpnare ptnare tnpare ntpare pntare nptare tanpre atnpre tnapre ntapre antpre natpre pantre apntre pnatre npatre anptre naptre rpante prante rapnte arpnte parnte aprnte rpnate prnate rnpate nrpate pnrate nprate ranpte arnpte rnapte nrapte anrpte narpte panrte apnrte pnarte nparte anprte naprte tepanr etpanr tpeanr pteanr eptanr petanr teapnr etapnr taepnr atepnr eatpnr aetpnr tpaenr ptaenr tapenr atpenr patenr aptenr epatnr peatnr eaptnr aeptnr paetnr apetnr tepnar etpnar tpenar ptenar eptnar petnar tenpar etnpar tnepar ntepar entpar netpar tpnear ptnear tnpear ntpear pntear nptear epntar pentar enptar neptar pnetar npetar teanpr etanpr taenpr atenpr eatnpr aetnpr tenapr etnapr tneapr nteapr entapr netapr tanepr atnepr tnaepr ntaepr antepr natepr eantpr aentpr enatpr neatpr anetpr naetpr tpaner ptaner tapner atpner patner aptner tpnaer ptnaer tnpaer ntpaer pntaer nptaer tanper atnper tnaper ntaper antper natper panter apnter pnater npater anpter napter epantr peantr eapntr aepntr paentr apentr epnatr penatr enpatr nepatr pneatr npeatr eanptr aenptr enaptr neaptr aneptr naeptr panetr apnetr pnaetr npaetr anpetr napetr repant erpant rpeant preant eprant perant reapnt erapnt raepnt arepnt earpnt aerpnt rpaent praent rapent arpent parent aprent eparnt pearnt eaprnt aeprnt paernt apernt repnat erpnat rpenat prenat eprnat pernat renpat ernpat rnepat nrepat enrpat nerpat rpneat prneat rnpeat nrpeat pnreat npreat epnrat penrat enprat neprat pnerat nperat reanpt eranpt raenpt arenpt earnpt aernpt renapt ernapt rneapt nreapt enrapt nerapt ranept arnept rnaept nraept anrept narept eanrpt aenrpt enarpt nearpt anerpt naerpt rpanet pranet rapnet arpnet parnet aprnet rpnaet prnaet rnpaet nrpaet pnraet npraet ranpet arnpet rnapet nrapet anrpet narpet panret apnret pnaret nparet anpret napret epanrt peanrt eapnrt aepnrt paenrt apenrt epnart penart enpart nepart pneart npeart eanprt aenprt enaprt neaprt aneprt naeprt panert apnert pnaert npaert anpert napert
Note: these 'words' (valid or invalid) are all the permutations of the word trepan. These words are obtained by scrambling the letters in trepan.